Long term strain gage monitoring was conducted on the reconstructed silo PC1 to track stress changes in the walls from variations in clinker loading levels and temperatures. Over one year, 16 strain gages at different heights measured stresses as the silo was filled from 5 to 47 meters and discharged. Results showed stresses increased with filling from -52 to 85 MPa and decreased from -29 to -59 MPa with discharge. Stresses also varied by height. Finite element modeling in ANSYS generally matched measured stresses but showed higher dispersion at greater heights. Monitoring provided data to evaluate stresses in the reconstructed silo under working conditions.
Over millions of people travel to Sri Lanka every year. This document provides travel tips for visiting Sri Lanka by summarizing various locations of interest and tour packages. Key locations mentioned include Meemure village in the Knuckles Mountain Range, Galle Fort built by the Portuguese and Dutch, the Temple of the Tooth in Kandy housing Buddha's tooth relic, and popular tour packages include day trips to Kandy, Sigiriya, and Nuwara Eliya in the tea country. Various activities are also recommended like water rafting, whale watching, and safaris in Yala National Park.
cranial fracture 41 pages evidence part 1 of 2 parts from mr. john g. davidoffjohn davidoff
The document discusses the results of a study on the impact of COVID-19 lockdowns on air pollution. The study found that lockdowns led to short-term reductions in nitrogen dioxide and fine particulate matter concentrations globally. However, the impacts on air quality were temporary and levels returned to pre-pandemic levels once restrictions were lifted and activity resumed.
Ujjwal has over 12 years of experience managing GIS and remote sensing projects related to hazard and risk assessment, vulnerability analysis, and spatial decision support systems. He has strong skills in project management, GIS software such as ArcGIS, spatial analysis, and developing web-based GIS systems. Some of his key projects include infrastructure management for a freight corridor project in India, coastal protection planning for 13 Indian states, and disaster risk assessment for countries in Asia, Africa, and the Americas.
This document contains the personal and professional details of T.A. Akhil. It includes his contact information, educational background which includes degrees in Interior Design and Business Administration. It outlines his over 5 years of experience as an Interior Designer and Graphic Designer in India and Dubai. His responsibilities included designing interiors, client management, 3D modeling, cost control, and more. The document also lists his technical skills such as CAD, 3DS Max, rendering software, and design programs.
Long term strain gage monitoring was conducted on the reconstructed silo PC1 to track stress changes in the walls from variations in clinker loading levels and temperatures. Over one year, 16 strain gages at different heights measured stresses as the silo was filled from 5 to 47 meters and discharged. Results showed stresses increased with filling from -52 to 85 MPa and decreased from -29 to -59 MPa with discharge. Stresses also varied by height. Finite element modeling in ANSYS generally matched measured stresses but showed higher dispersion at greater heights. Monitoring provided data to evaluate stresses in the reconstructed silo under working conditions.
Over millions of people travel to Sri Lanka every year. This document provides travel tips for visiting Sri Lanka by summarizing various locations of interest and tour packages. Key locations mentioned include Meemure village in the Knuckles Mountain Range, Galle Fort built by the Portuguese and Dutch, the Temple of the Tooth in Kandy housing Buddha's tooth relic, and popular tour packages include day trips to Kandy, Sigiriya, and Nuwara Eliya in the tea country. Various activities are also recommended like water rafting, whale watching, and safaris in Yala National Park.
cranial fracture 41 pages evidence part 1 of 2 parts from mr. john g. davidoffjohn davidoff
The document discusses the results of a study on the impact of COVID-19 lockdowns on air pollution. The study found that lockdowns led to short-term reductions in nitrogen dioxide and fine particulate matter concentrations globally. However, the impacts on air quality were temporary and levels returned to pre-pandemic levels once restrictions were lifted and activity resumed.
Ujjwal has over 12 years of experience managing GIS and remote sensing projects related to hazard and risk assessment, vulnerability analysis, and spatial decision support systems. He has strong skills in project management, GIS software such as ArcGIS, spatial analysis, and developing web-based GIS systems. Some of his key projects include infrastructure management for a freight corridor project in India, coastal protection planning for 13 Indian states, and disaster risk assessment for countries in Asia, Africa, and the Americas.
This document contains the personal and professional details of T.A. Akhil. It includes his contact information, educational background which includes degrees in Interior Design and Business Administration. It outlines his over 5 years of experience as an Interior Designer and Graphic Designer in India and Dubai. His responsibilities included designing interiors, client management, 3D modeling, cost control, and more. The document also lists his technical skills such as CAD, 3DS Max, rendering software, and design programs.
2024 State of Marketing Report – by HubspotMarius Sescu
https://www.hubspot.com/state-of-marketing
· Scaling relationships and proving ROI
· Social media is the place for search, sales, and service
· Authentic influencer partnerships fuel brand growth
· The strongest connections happen via call, click, chat, and camera.
· Time saved with AI leads to more creative work
· Seeking: A single source of truth
· TLDR; Get on social, try AI, and align your systems.
· More human marketing, powered by robots
ChatGPT is a revolutionary addition to the world since its introduction in 2022. A big shift in the sector of information gathering and processing happened because of this chatbot. What is the story of ChatGPT? How is the bot responding to prompts and generating contents? Swipe through these slides prepared by Expeed Software, a web development company regarding the development and technical intricacies of ChatGPT!
Product Design Trends in 2024 | Teenage EngineeringsPixeldarts
The realm of product design is a constantly changing environment where technology and style intersect. Every year introduces fresh challenges and exciting trends that mold the future of this captivating art form. In this piece, we delve into the significant trends set to influence the look and functionality of product design in the year 2024.
How Race, Age and Gender Shape Attitudes Towards Mental HealthThinkNow
Mental health has been in the news quite a bit lately. Dozens of U.S. states are currently suing Meta for contributing to the youth mental health crisis by inserting addictive features into their products, while the U.S. Surgeon General is touring the nation to bring awareness to the growing epidemic of loneliness and isolation. The country has endured periods of low national morale, such as in the 1970s when high inflation and the energy crisis worsened public sentiment following the Vietnam War. The current mood, however, feels different. Gallup recently reported that national mental health is at an all-time low, with few bright spots to lift spirits.
To better understand how Americans are feeling and their attitudes towards mental health in general, ThinkNow conducted a nationally representative quantitative survey of 1,500 respondents and found some interesting differences among ethnic, age and gender groups.
Technology
For example, 52% agree that technology and social media have a negative impact on mental health, but when broken out by race, 61% of Whites felt technology had a negative effect, and only 48% of Hispanics thought it did.
While technology has helped us keep in touch with friends and family in faraway places, it appears to have degraded our ability to connect in person. Staying connected online is a double-edged sword since the same news feed that brings us pictures of the grandkids and fluffy kittens also feeds us news about the wars in Israel and Ukraine, the dysfunction in Washington, the latest mass shooting and the climate crisis.
Hispanics may have a built-in defense against the isolation technology breeds, owing to their large, multigenerational households, strong social support systems, and tendency to use social media to stay connected with relatives abroad.
Age and Gender
When asked how individuals rate their mental health, men rate it higher than women by 11 percentage points, and Baby Boomers rank it highest at 83%, saying it’s good or excellent vs. 57% of Gen Z saying the same.
Gen Z spends the most amount of time on social media, so the notion that social media negatively affects mental health appears to be correlated. Unfortunately, Gen Z is also the generation that’s least comfortable discussing mental health concerns with healthcare professionals. Only 40% of them state they’re comfortable discussing their issues with a professional compared to 60% of Millennials and 65% of Boomers.
Race Affects Attitudes
As seen in previous research conducted by ThinkNow, Asian Americans lag other groups when it comes to awareness of mental health issues. Twenty-four percent of Asian Americans believe that having a mental health issue is a sign of weakness compared to the 16% average for all groups. Asians are also considerably less likely to be aware of mental health services in their communities (42% vs. 55%) and most likely to seek out information on social media (51% vs. 35%).
AI Trends in Creative Operations 2024 by Artwork Flow.pdfmarketingartwork
Creative operations teams expect increased AI use in 2024. Currently, over half of tasks are not AI-enabled, but this is expected to decrease in the coming year. ChatGPT is the most popular AI tool currently. Business leaders are more actively exploring AI benefits than individual contributors. Most respondents do not believe AI will impact workforce size in 2024. However, some inhibitions still exist around AI accuracy and lack of understanding. Creatives primarily want to use AI to save time on mundane tasks and boost productivity.
Organizational culture includes values, norms, systems, symbols, language, assumptions, beliefs, and habits that influence employee behaviors and how people interpret those behaviors. It is important because culture can help or hinder a company's success. Some key aspects of Netflix's culture that help it achieve results include hiring smartly so every position has stars, focusing on attitude over just aptitude, and having a strict policy against peacocks, whiners, and jerks.
PEPSICO Presentation to CAGNY Conference Feb 2024Neil Kimberley
PepsiCo provided a safe harbor statement noting that any forward-looking statements are based on currently available information and are subject to risks and uncertainties. It also provided information on non-GAAP measures and directing readers to its website for disclosure and reconciliation. The document then discussed PepsiCo's business overview, including that it is a global beverage and convenient food company with iconic brands, $91 billion in net revenue in 2023, and nearly $14 billion in core operating profit. It operates through a divisional structure with a focus on local consumers.
Content Methodology: A Best Practices Report (Webinar)contently
This document provides an overview of content methodology best practices. It defines content methodology as establishing objectives, KPIs, and a culture of continuous learning and iteration. An effective methodology focuses on connecting with audiences, creating optimal content, and optimizing processes. It also discusses why a methodology is needed due to the competitive landscape, proliferation of channels, and opportunities for improvement. Components of an effective methodology include defining objectives and KPIs, audience analysis, identifying opportunities, and evaluating resources. The document concludes with recommendations around creating a content plan, testing and optimizing content over 90 days.
How to Prepare For a Successful Job Search for 2024Albert Qian
The document provides guidance on preparing a job search for 2024. It discusses the state of the job market, focusing on growth in AI and healthcare but also continued layoffs. It recommends figuring out what you want to do by researching interests and skills, then conducting informational interviews. The job search should involve building a personal brand on LinkedIn, actively applying to jobs, tailoring resumes and interviews, maintaining job hunting as a habit, and continuing self-improvement. Once hired, the document advises setting new goals and keeping skills and networking active in case of future opportunities.
A report by thenetworkone and Kurio.
The contributing experts and agencies are (in an alphabetical order): Sylwia Rytel, Social Media Supervisor, 180heartbeats + JUNG v MATT (PL), Sharlene Jenner, Vice President - Director of Engagement Strategy, Abelson Taylor (USA), Alex Casanovas, Digital Director, Atrevia (ES), Dora Beilin, Senior Social Strategist, Barrett Hoffher (USA), Min Seo, Campaign Director, Brand New Agency (KR), Deshé M. Gully, Associate Strategist, Day One Agency (USA), Francesca Trevisan, Strategist, Different (IT), Trevor Crossman, CX and Digital Transformation Director; Olivia Hussey, Strategic Planner; Simi Srinarula, Social Media Manager, The Hallway (AUS), James Hebbert, Managing Director, Hylink (CN / UK), Mundy Álvarez, Planning Director; Pedro Rojas, Social Media Manager; Pancho González, CCO, Inbrax (CH), Oana Oprea, Head of Digital Planning, Jam Session Agency (RO), Amy Bottrill, Social Account Director, Launch (UK), Gaby Arriaga, Founder, Leonardo1452 (MX), Shantesh S Row, Creative Director, Liwa (UAE), Rajesh Mehta, Chief Strategy Officer; Dhruv Gaur, Digital Planning Lead; Leonie Mergulhao, Account Supervisor - Social Media & PR, Medulla (IN), Aurelija Plioplytė, Head of Digital & Social, Not Perfect (LI), Daiana Khaidargaliyeva, Account Manager, Osaka Labs (UK / USA), Stefanie Söhnchen, Vice President Digital, PIABO Communications (DE), Elisabeth Winiartati, Managing Consultant, Head of Global Integrated Communications; Lydia Aprina, Account Manager, Integrated Marketing and Communications; Nita Prabowo, Account Manager, Integrated Marketing and Communications; Okhi, Web Developer, PNTR Group (ID), Kei Obusan, Insights Director; Daffi Ranandi, Insights Manager, Radarr (SG), Gautam Reghunath, Co-founder & CEO, Talented (IN), Donagh Humphreys, Head of Social and Digital Innovation, THINKHOUSE (IRE), Sarah Yim, Strategy Director, Zulu Alpha Kilo (CA).
Trends In Paid Search: Navigating The Digital Landscape In 2024Search Engine Journal
The search marketing landscape is evolving rapidly with new technologies, and professionals, like you, rely on innovative paid search strategies to meet changing demands.
It’s important that you’re ready to implement new strategies in 2024.
Check this out and learn the top trends in paid search advertising that are expected to gain traction, so you can drive higher ROI more efficiently in 2024.
You’ll learn:
- The latest trends in AI and automation, and what this means for an evolving paid search ecosystem.
- New developments in privacy and data regulation.
- Emerging ad formats that are expected to make an impact next year.
Watch Sreekant Lanka from iQuanti and Irina Klein from OneMain Financial as they dive into the future of paid search and explore the trends, strategies, and technologies that will shape the search marketing landscape.
If you’re looking to assess your paid search strategy and design an industry-aligned plan for 2024, then this webinar is for you.
5 Public speaking tips from TED - Visualized summarySpeakerHub
From their humble beginnings in 1984, TED has grown into the world’s most powerful amplifier for speakers and thought-leaders to share their ideas. They have over 2,400 filmed talks (not including the 30,000+ TEDx videos) freely available online, and have hosted over 17,500 events around the world.
With over one billion views in a year, it’s no wonder that so many speakers are looking to TED for ideas on how to share their message more effectively.
The article “5 Public-Speaking Tips TED Gives Its Speakers”, by Carmine Gallo for Forbes, gives speakers five practical ways to connect with their audience, and effectively share their ideas on stage.
Whether you are gearing up to get on a TED stage yourself, or just want to master the skills that so many of their speakers possess, these tips and quotes from Chris Anderson, the TED Talks Curator, will encourage you to make the most impactful impression on your audience.
See the full article and more summaries like this on SpeakerHub here: https://speakerhub.com/blog/5-presentation-tips-ted-gives-its-speakers
See the original article on Forbes here:
http://www.forbes.com/forbes/welcome/?toURL=http://www.forbes.com/sites/carminegallo/2016/05/06/5-public-speaking-tips-ted-gives-its-speakers/&refURL=&referrer=#5c07a8221d9b
ChatGPT and the Future of Work - Clark Boyd Clark Boyd
Everyone is in agreement that ChatGPT (and other generative AI tools) will shape the future of work. Yet there is little consensus on exactly how, when, and to what extent this technology will change our world.
Businesses that extract maximum value from ChatGPT will use it as a collaborative tool for everything from brainstorming to technical maintenance.
For individuals, now is the time to pinpoint the skills the future professional will need to thrive in the AI age.
Check out this presentation to understand what ChatGPT is, how it will shape the future of work, and how you can prepare to take advantage.
The document provides career advice for getting into the tech field, including:
- Doing projects and internships in college to build a portfolio.
- Learning about different roles and technologies through industry research.
- Contributing to open source projects to build experience and network.
- Developing a personal brand through a website and social media presence.
- Networking through events, communities, and finding a mentor.
- Practicing interviews through mock interviews and whiteboarding coding questions.
Google's Just Not That Into You: Understanding Core Updates & Search IntentLily Ray
1. Core updates from Google periodically change how its algorithms assess and rank websites and pages. This can impact rankings through shifts in user intent, site quality issues being caught up to, world events influencing queries, and overhauls to search like the E-A-T framework.
2. There are many possible user intents beyond just transactional, navigational and informational. Identifying intent shifts is important during core updates. Sites may need to optimize for new intents through different content types and sections.
3. Responding effectively to core updates requires analyzing "before and after" data to understand changes, identifying new intents or page types, and ensuring content matches appropriate intents across video, images, knowledge graphs and more.
A brief introduction to DataScience with explaining of the concepts, algorithms, machine learning, supervised and unsupervised learning, clustering, statistics, data preprocessing, real-world applications etc.
It's part of a Data Science Corner Campaign where I will be discussing the fundamentals of DataScience, AIML, Statistics etc.
Time Management & Productivity - Best PracticesVit Horky
Here's my presentation on by proven best practices how to manage your work time effectively and how to improve your productivity. It includes practical tips and how to use tools such as Slack, Google Apps, Hubspot, Google Calendar, Gmail and others.
The six step guide to practical project managementMindGenius
The six step guide to practical project management
If you think managing projects is too difficult, think again.
We’ve stripped back project management processes to the
basics – to make it quicker and easier, without sacrificing
the vital ingredients for success.
“If you’re looking for some real-world guidance, then The Six Step Guide to Practical Project Management will help.”
Dr Andrew Makar, Tactical Project Management
2024 State of Marketing Report – by HubspotMarius Sescu
https://www.hubspot.com/state-of-marketing
· Scaling relationships and proving ROI
· Social media is the place for search, sales, and service
· Authentic influencer partnerships fuel brand growth
· The strongest connections happen via call, click, chat, and camera.
· Time saved with AI leads to more creative work
· Seeking: A single source of truth
· TLDR; Get on social, try AI, and align your systems.
· More human marketing, powered by robots
ChatGPT is a revolutionary addition to the world since its introduction in 2022. A big shift in the sector of information gathering and processing happened because of this chatbot. What is the story of ChatGPT? How is the bot responding to prompts and generating contents? Swipe through these slides prepared by Expeed Software, a web development company regarding the development and technical intricacies of ChatGPT!
Product Design Trends in 2024 | Teenage EngineeringsPixeldarts
The realm of product design is a constantly changing environment where technology and style intersect. Every year introduces fresh challenges and exciting trends that mold the future of this captivating art form. In this piece, we delve into the significant trends set to influence the look and functionality of product design in the year 2024.
How Race, Age and Gender Shape Attitudes Towards Mental HealthThinkNow
Mental health has been in the news quite a bit lately. Dozens of U.S. states are currently suing Meta for contributing to the youth mental health crisis by inserting addictive features into their products, while the U.S. Surgeon General is touring the nation to bring awareness to the growing epidemic of loneliness and isolation. The country has endured periods of low national morale, such as in the 1970s when high inflation and the energy crisis worsened public sentiment following the Vietnam War. The current mood, however, feels different. Gallup recently reported that national mental health is at an all-time low, with few bright spots to lift spirits.
To better understand how Americans are feeling and their attitudes towards mental health in general, ThinkNow conducted a nationally representative quantitative survey of 1,500 respondents and found some interesting differences among ethnic, age and gender groups.
Technology
For example, 52% agree that technology and social media have a negative impact on mental health, but when broken out by race, 61% of Whites felt technology had a negative effect, and only 48% of Hispanics thought it did.
While technology has helped us keep in touch with friends and family in faraway places, it appears to have degraded our ability to connect in person. Staying connected online is a double-edged sword since the same news feed that brings us pictures of the grandkids and fluffy kittens also feeds us news about the wars in Israel and Ukraine, the dysfunction in Washington, the latest mass shooting and the climate crisis.
Hispanics may have a built-in defense against the isolation technology breeds, owing to their large, multigenerational households, strong social support systems, and tendency to use social media to stay connected with relatives abroad.
Age and Gender
When asked how individuals rate their mental health, men rate it higher than women by 11 percentage points, and Baby Boomers rank it highest at 83%, saying it’s good or excellent vs. 57% of Gen Z saying the same.
Gen Z spends the most amount of time on social media, so the notion that social media negatively affects mental health appears to be correlated. Unfortunately, Gen Z is also the generation that’s least comfortable discussing mental health concerns with healthcare professionals. Only 40% of them state they’re comfortable discussing their issues with a professional compared to 60% of Millennials and 65% of Boomers.
Race Affects Attitudes
As seen in previous research conducted by ThinkNow, Asian Americans lag other groups when it comes to awareness of mental health issues. Twenty-four percent of Asian Americans believe that having a mental health issue is a sign of weakness compared to the 16% average for all groups. Asians are also considerably less likely to be aware of mental health services in their communities (42% vs. 55%) and most likely to seek out information on social media (51% vs. 35%).
AI Trends in Creative Operations 2024 by Artwork Flow.pdfmarketingartwork
Creative operations teams expect increased AI use in 2024. Currently, over half of tasks are not AI-enabled, but this is expected to decrease in the coming year. ChatGPT is the most popular AI tool currently. Business leaders are more actively exploring AI benefits than individual contributors. Most respondents do not believe AI will impact workforce size in 2024. However, some inhibitions still exist around AI accuracy and lack of understanding. Creatives primarily want to use AI to save time on mundane tasks and boost productivity.
Organizational culture includes values, norms, systems, symbols, language, assumptions, beliefs, and habits that influence employee behaviors and how people interpret those behaviors. It is important because culture can help or hinder a company's success. Some key aspects of Netflix's culture that help it achieve results include hiring smartly so every position has stars, focusing on attitude over just aptitude, and having a strict policy against peacocks, whiners, and jerks.
PEPSICO Presentation to CAGNY Conference Feb 2024Neil Kimberley
PepsiCo provided a safe harbor statement noting that any forward-looking statements are based on currently available information and are subject to risks and uncertainties. It also provided information on non-GAAP measures and directing readers to its website for disclosure and reconciliation. The document then discussed PepsiCo's business overview, including that it is a global beverage and convenient food company with iconic brands, $91 billion in net revenue in 2023, and nearly $14 billion in core operating profit. It operates through a divisional structure with a focus on local consumers.
Content Methodology: A Best Practices Report (Webinar)contently
This document provides an overview of content methodology best practices. It defines content methodology as establishing objectives, KPIs, and a culture of continuous learning and iteration. An effective methodology focuses on connecting with audiences, creating optimal content, and optimizing processes. It also discusses why a methodology is needed due to the competitive landscape, proliferation of channels, and opportunities for improvement. Components of an effective methodology include defining objectives and KPIs, audience analysis, identifying opportunities, and evaluating resources. The document concludes with recommendations around creating a content plan, testing and optimizing content over 90 days.
How to Prepare For a Successful Job Search for 2024Albert Qian
The document provides guidance on preparing a job search for 2024. It discusses the state of the job market, focusing on growth in AI and healthcare but also continued layoffs. It recommends figuring out what you want to do by researching interests and skills, then conducting informational interviews. The job search should involve building a personal brand on LinkedIn, actively applying to jobs, tailoring resumes and interviews, maintaining job hunting as a habit, and continuing self-improvement. Once hired, the document advises setting new goals and keeping skills and networking active in case of future opportunities.
A report by thenetworkone and Kurio.
The contributing experts and agencies are (in an alphabetical order): Sylwia Rytel, Social Media Supervisor, 180heartbeats + JUNG v MATT (PL), Sharlene Jenner, Vice President - Director of Engagement Strategy, Abelson Taylor (USA), Alex Casanovas, Digital Director, Atrevia (ES), Dora Beilin, Senior Social Strategist, Barrett Hoffher (USA), Min Seo, Campaign Director, Brand New Agency (KR), Deshé M. Gully, Associate Strategist, Day One Agency (USA), Francesca Trevisan, Strategist, Different (IT), Trevor Crossman, CX and Digital Transformation Director; Olivia Hussey, Strategic Planner; Simi Srinarula, Social Media Manager, The Hallway (AUS), James Hebbert, Managing Director, Hylink (CN / UK), Mundy Álvarez, Planning Director; Pedro Rojas, Social Media Manager; Pancho González, CCO, Inbrax (CH), Oana Oprea, Head of Digital Planning, Jam Session Agency (RO), Amy Bottrill, Social Account Director, Launch (UK), Gaby Arriaga, Founder, Leonardo1452 (MX), Shantesh S Row, Creative Director, Liwa (UAE), Rajesh Mehta, Chief Strategy Officer; Dhruv Gaur, Digital Planning Lead; Leonie Mergulhao, Account Supervisor - Social Media & PR, Medulla (IN), Aurelija Plioplytė, Head of Digital & Social, Not Perfect (LI), Daiana Khaidargaliyeva, Account Manager, Osaka Labs (UK / USA), Stefanie Söhnchen, Vice President Digital, PIABO Communications (DE), Elisabeth Winiartati, Managing Consultant, Head of Global Integrated Communications; Lydia Aprina, Account Manager, Integrated Marketing and Communications; Nita Prabowo, Account Manager, Integrated Marketing and Communications; Okhi, Web Developer, PNTR Group (ID), Kei Obusan, Insights Director; Daffi Ranandi, Insights Manager, Radarr (SG), Gautam Reghunath, Co-founder & CEO, Talented (IN), Donagh Humphreys, Head of Social and Digital Innovation, THINKHOUSE (IRE), Sarah Yim, Strategy Director, Zulu Alpha Kilo (CA).
Trends In Paid Search: Navigating The Digital Landscape In 2024Search Engine Journal
The search marketing landscape is evolving rapidly with new technologies, and professionals, like you, rely on innovative paid search strategies to meet changing demands.
It’s important that you’re ready to implement new strategies in 2024.
Check this out and learn the top trends in paid search advertising that are expected to gain traction, so you can drive higher ROI more efficiently in 2024.
You’ll learn:
- The latest trends in AI and automation, and what this means for an evolving paid search ecosystem.
- New developments in privacy and data regulation.
- Emerging ad formats that are expected to make an impact next year.
Watch Sreekant Lanka from iQuanti and Irina Klein from OneMain Financial as they dive into the future of paid search and explore the trends, strategies, and technologies that will shape the search marketing landscape.
If you’re looking to assess your paid search strategy and design an industry-aligned plan for 2024, then this webinar is for you.
5 Public speaking tips from TED - Visualized summarySpeakerHub
From their humble beginnings in 1984, TED has grown into the world’s most powerful amplifier for speakers and thought-leaders to share their ideas. They have over 2,400 filmed talks (not including the 30,000+ TEDx videos) freely available online, and have hosted over 17,500 events around the world.
With over one billion views in a year, it’s no wonder that so many speakers are looking to TED for ideas on how to share their message more effectively.
The article “5 Public-Speaking Tips TED Gives Its Speakers”, by Carmine Gallo for Forbes, gives speakers five practical ways to connect with their audience, and effectively share their ideas on stage.
Whether you are gearing up to get on a TED stage yourself, or just want to master the skills that so many of their speakers possess, these tips and quotes from Chris Anderson, the TED Talks Curator, will encourage you to make the most impactful impression on your audience.
See the full article and more summaries like this on SpeakerHub here: https://speakerhub.com/blog/5-presentation-tips-ted-gives-its-speakers
See the original article on Forbes here:
http://www.forbes.com/forbes/welcome/?toURL=http://www.forbes.com/sites/carminegallo/2016/05/06/5-public-speaking-tips-ted-gives-its-speakers/&refURL=&referrer=#5c07a8221d9b
ChatGPT and the Future of Work - Clark Boyd Clark Boyd
Everyone is in agreement that ChatGPT (and other generative AI tools) will shape the future of work. Yet there is little consensus on exactly how, when, and to what extent this technology will change our world.
Businesses that extract maximum value from ChatGPT will use it as a collaborative tool for everything from brainstorming to technical maintenance.
For individuals, now is the time to pinpoint the skills the future professional will need to thrive in the AI age.
Check out this presentation to understand what ChatGPT is, how it will shape the future of work, and how you can prepare to take advantage.
The document provides career advice for getting into the tech field, including:
- Doing projects and internships in college to build a portfolio.
- Learning about different roles and technologies through industry research.
- Contributing to open source projects to build experience and network.
- Developing a personal brand through a website and social media presence.
- Networking through events, communities, and finding a mentor.
- Practicing interviews through mock interviews and whiteboarding coding questions.
Google's Just Not That Into You: Understanding Core Updates & Search IntentLily Ray
1. Core updates from Google periodically change how its algorithms assess and rank websites and pages. This can impact rankings through shifts in user intent, site quality issues being caught up to, world events influencing queries, and overhauls to search like the E-A-T framework.
2. There are many possible user intents beyond just transactional, navigational and informational. Identifying intent shifts is important during core updates. Sites may need to optimize for new intents through different content types and sections.
3. Responding effectively to core updates requires analyzing "before and after" data to understand changes, identifying new intents or page types, and ensuring content matches appropriate intents across video, images, knowledge graphs and more.
A brief introduction to DataScience with explaining of the concepts, algorithms, machine learning, supervised and unsupervised learning, clustering, statistics, data preprocessing, real-world applications etc.
It's part of a Data Science Corner Campaign where I will be discussing the fundamentals of DataScience, AIML, Statistics etc.
Time Management & Productivity - Best PracticesVit Horky
Here's my presentation on by proven best practices how to manage your work time effectively and how to improve your productivity. It includes practical tips and how to use tools such as Slack, Google Apps, Hubspot, Google Calendar, Gmail and others.
The six step guide to practical project managementMindGenius
The six step guide to practical project management
If you think managing projects is too difficult, think again.
We’ve stripped back project management processes to the
basics – to make it quicker and easier, without sacrificing
the vital ingredients for success.
“If you’re looking for some real-world guidance, then The Six Step Guide to Practical Project Management will help.”
Dr Andrew Makar, Tactical Project Management
Beginners Guide to TikTok for Search - Rachel Pearson - We are Tilt __ Bright...
Lukas Kowalski_ARTICLE
1. JUNIORSTAV 2011
2.2 Konstrukce kovové, dřevěné a kompozitní
1
r
t
Ecr 605.0
VPLYV ORTOGONÁLNYCH VÝSTUH NA STRATU STABILITY VALCOVEJ ŠKRUPINY PRI OSOVOM
TLAKU
IMPACT OF THE ORTHOGONAL STIFFENERS ON STABILITY OF THE CYLINDRICAL SHELL BY AXIAL
COMPRESSION
Lukáš Kowalski1
Abstract/Zusammenfassung
In recent years number of silo failures were noticed. From the experiments and researches resulted some common
characteristics – reasons of accidents. Clinker silo PC1 in company Holcim, Rohoznik was designed in early 1970ties.
During years, major cracks that denied further usability occurred. In the years 2006/7 reconstruction works were done.
Vertical and horizontal restraints were welded on construction to increase section area – resistance and stability as well.
Subject of the article is to check norm calculation (EC 1993-1-6) and compare it with solution from FEM program
ANSYS. Unstiffened construction and various types of stiffening (stiffening with horizontal rings, stiffening with
vertical beams, orthogonal stiffened construction) of the cylindrical shell were modelled in FEM program ANSYS.
Keywords/Schlüsselwörter
silo, cylindrical shell, orthogonal stiffeners, buckling load, finite element method
1.1 Úvod
Problémy stability štíhlych valcových škrupín boli spracované už v predchádzajúcom storočí. Ich masový
rozmach nastal s rozvojom aeronautiky v období po druhej svetovej vojne. Prvé teoretické bádania pracovali s teóriou
malých deformácií (deformácie sú menšie ako hrúbka škrupiny). Pre výpočet kritického napätia hladkej valcovej
škrupiny vydúvaním geometricky lineárnou metódou platí známy vzťah z ktorého vidno nepriamo úmernú lineárnu
závislosť kritického napätia na štíhlosti konštrukcie
(1)
Okrem teoretických výpočtov bolo vykonané značné množstvo experimentálnych skúšok, ktoré preukázali rozpor
medzi teoretickými hodnotami kritického napätia a realitou. V skutočnosti bolo preukázané, že vybočenie nastane náhle
pri hodnotách cca 0,1 až 0,6 násobku teoretickej hodnoty scr , v závislosti na pomere r/h a hrúbke steny škrupiny.
Zásadné spresnenie nastalo s rozvojom metódy veľkých deformácií v období po druhej svetovej vojne (Kárman).
Výsledky jeho výskumu priniesli pozmenený vzťah (1) s koeficientom k podľa pomeru r/t
(2)
r polomer škrupiny
h výška škrupiny
t hrúbka škrupony
E modul pružnosti konštr. materiálu škrupiny
Tab. 1 Hodnoty koeficientu k pre výpočet kritického napätia pri vydúvaní [2]
Pri tejto metóde môžu deformácie dosiahnuť rádu hrúbky škrupiny. Práve vplyv imperfekcií má zásadný vplyv na
kritické napätie pri strate stability vydúvaním štíhlej škrupiny.
Hoci je problematika vertikálnych a horizontálnych výstuh v literatúre už dávnejšie spracovaná v oblasti ortogonálnych
výstuh je stále biele miesto. Tento článok sa zaoberá vplyvom ortogonálnych výstuh na tvar vybočenia ako aj na
únosnosť škrupinovej konštrukcie. V tomto štádiu hľadá hodnotu bifurkačného bodu, výpočty sú spracované
geometricky lineárnou metódou.
1
Lukáš Kowalski, Ing., Slovenská technická univeryita v Bratislave, Stavebná fakulta, Katedra kovových a drevených konštrukcií, Radlinského 11,
813 68 Bratislava, lukas.kowalski@stuba.sk
r/t 250 500 750 1000 1500
k 0,18 0,14 0,12 0,10 0,09
r
t
Ekcr .
2. JUNIORSTAV 2011
2.2 Konstrukce kovové, dřevěné a kompozitní
2
1.2 Silo na slinok PC1
V článku je popísaná oceľová cylindrická škrupinová konštrukcia sila. So spolupôsobením strešnej konštrukcie nie je
uvažované z dôvodu možnosti lepšieho porovnania výpočtových postupov pre valcové škrupiny.
Predmetné silo na slinok vo firme HOLCIM, Rohožník bolo naprojektované firmou PIO KERAMOPROJEKT v
Trenčíne v roku 1973 (ČSN 73 0035). Konštrukcia slúži na skladovanie slinku v cementárni Holcim v Rohožníku.
Priemer sila je 36m, výška steny sila je 41m (50,525m po vrchol strechy). Celková kapacita sila je 60000t slinku.
Silo bolo vyrobené technológiou zvárania z plechov ocele (oceľ zodpovedajúca triede S275, fy = 275 MPa, fu = 430
MPa) s po výške premennou hrúbkou (13mm - 33mm). [8]
Obr. 1 Pohľad na pôvodnú konštrukciu sila Obr. 2 Pohľad na rekonštruované silo
V priebehu užívania sa na ňom vyskytli niektoré závažné nedostatky, ktoré znemožnili ďalšie užívanie sila. Išlo najmä
o vznik deformácií, výrazných trhlín až do výšky 6000mm a v mieste zvislej trhliny pretrhnutie dolného nosného
prstenca. Ako súhrn všetkých týchto požiadaviek bol v roku 2006 vypracovaný projekt zosilnenia konštrukcie sila
(projektant KKDK, SvF STU Bratislava). Ako výstuhy boli navrhnuté a realizované ortotropné stužujúce nosníky
privarené na stenu sila. Vo vertikálnom smere boli navrhnuté a navarené plechy s priečnym rezom variabilnom po
výške rozmerov 300mm x 30mm, 220mm x 22mm, 180mm x 18mm. V horizontálnom smere bolo vystuženie
realizované navarením zváraných nosníkov tvaru L425x12-250x25 a opásaním sila prstencami s rozmermi 250mm x
20mm. [8]. Vertikálne výstuhy okrem zvýšenia stabilitnej odolnosti zmenou statickej schémy konštrukcie aj priamo
zvyšujú prierezovú plochu steny. Horizontálne výstuhy sú inštalované najmä na udržanie oválnosti priečneho rezu.
Obr. 3 Geometria a rozmery sila PC1 Obr. 4 Schéma výpočtového modelu s približným
tvarom zaťaženia
3. JUNIORSTAV 2011
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3
1.3 FEM model cylindrickej konštrukcie sila
Konštrukcia sila je modelovaná v cylindrickom súradnom systéme pomocou škrupinových kvadratických elementov
SHELL281 (8 uzlový škrupinový element), výstuhy sú modelované kvadratickými prútovými prvkami BEAM189 (3
uzlový líniový prvok). Plošné škrupinové prvky majú zadanú reálnu hrúbku steny od 10mm-29mm. Z dôvodu
zjednodušenia konečno prvkového modelu pre stabilitnú analýzu je modelovaná len stenová časť konštrukcie. Taktiež
nie sú na stenu sila vnášané reakcie od strešnej konštrukcie.
Oceľ je vystihnutá pružno - plastickým bilineárnym pracovným diagramom s lineárnym spevnením s primárnou vetvou
E = 210.109
Pa, sekundárnou E = 210.107
Pa. Medza klzu ocele je fy = 275MPa. Delenie na konečno prvkové elementy
je nerovnomerné so zahustením v spodnej polovici sila. Konštrukcia je na úrovni 0.000m kĺbovo podopretá, v smeroch
X, Y, Z. Horný okraj je stužený prstencovou výstuhou tvaru L. Konštrukcia je zaťažená vlastnou tiažou, hustota ocele
r=7850 kg/m3
, hodnota tiažového zrýchlenia g=10m/s2
. Pre stabilitný výpočet nebolo uvažované s užitočným
zaťažením od skladovaného slinku (horizontálny tlak na stenu, trecia trakcia). Pre konštrukcie zaťažené vnútorným
pretlakom norma EC 1993-1-6 dovoľuje neuvažovať s týmto zaťažením. Zjednodušenie je možno zaviesť, lebo
konštukcia má tendenciu vybočiť pre ňu v energeticky najvýhodnejšom tvare, t.j. smerujúc do vnútra valcovej škrupiny,
kde by užitočné zaťaženie náplňou pôsobilo proti smeru vybočenia stabilizujúco.
Obr. 5 Pohľad na FEM model hladkého sila
s koncovým prstencom
Obr. 6 Pohľad na ortogonálne vystužené silo
Článok porovnáva výsledky výpočtových postupov podľa súboru noriem EC (EC 1993-1-6) s výsledkami výpočtov
pomocou metódy konečných prvkov (ANSYS). Sú uvedené výsledky modelovania hľadania kritického zaťaženia
valcovej konštrukcie sila (d=36m, h=41m, konštr. mat. oceľ) LBA - MNA analýzou (geometricky lineárna analýza
s hľadaním bifurkačného bodu, materiálovo nelineárna analýza) bez a s uvážením ortogonálnych výstuh. Porovnáva
tvary vybočenia konštrukcie pred a po inštalovaní horizontálnych a vertikálnych výstuh. Ako výsledok analýzy sú
uvedené násobitele zaťaženia, ktorými je nutné prenásobiť pôsobiace zaťaženie, aby bolo dosiahnuté kritické napätie pri
vydúvaní. Výsledky sú uvedené pre 5 prvých tvarov vybočenia.
Násobiteľ hodnoty
zaťaženia pri
vydúvaní
Cylindrická škrupina, d = 36m, h = 41m, oceľ S275, hrúbka 10-29mm,
typ zaťaženia – osový tlak, LBA-MNA
Č. tvaru vybočenia Nevystužená so
stuž. prstencom
Vertikálne výstuhy so
stuž. prstencom
Horizontálne
výstuhy
Ortotropné výstuhy
1 93,359 164,96 85,627 158,41
2 93,376 164,99 85,645 158,52
3 93,514 167,07 85,807 158,54
4 93,517 167,08 85,120 158,86
5 93,596 170,6 85,838 158,91
Tab. 2 Násobiteľe zaťaženia pri strate stability
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Obr. 7 Tvar straty stability, pôdorys, hladká
konštrukcia s koncovou obručou
Obr. 9 Tvar straty stability, pôdorys, konštrukcia
vystužená vertikálnymi rebrami
Obr. 8 Tvar straty stability, pohľad, hladká konštrukcia
s koncovou obručou
Obr. 10 Tvar straty stability, pohľad, konštrukcia
vystužená vertikálnymi rebrami
Obr. 11 Tvar straty stability, pôdorys, konštrukcia
vystužená horizontálnymi rebrami
Obr. 12 Tvar straty stability, pohľad, silo vystužené
horizontálnymi prstencami
Obr. 13 Tvar straty stability, pôdorys, ortotropne
vystužená konštrukcia
Obr. 14 Tvar straty stability, pohľad, ortotropne
vystužená konštrukcia
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5
Výsledky hľadania tvarou vybočenia vydúvaním sú uvedené v tabuľke a na obrázkoch na predchádzajúcej strane.
Výsledky analýzu sú parametre, ktorými je potrebné vynásobiť zaťaženie pôsobiace na konštrukciu, aby bolo
dosiahnuté kritické napätie pri vydúvaní.
Boli riešené 3 varianty vystuženia škrupinovej konštrukcie (vystuženie horizontálnymi prstencami, vertikálne
vystužená valcová škrupina, ortotropne vystužená škrupina) ako aj nevystužená valcová škrupinová konštrukcia (hladká
škrupina s stužujúcimi rebrami na okrajoch). Dá sa skonštatovať, že pri vystužení horného okraju škrupiny stužujúcim
prstencom nenastáva na vyšetrovanej konštrukcií globálna strata stability. V prípadoch nevystuženej, vystuženej
horizontálnymi výstuhami a ortotropne vystuženej škrupiny nastáva lokálna strata stability približne v spodnej polovici
škrupinovej konštrukcie. Konštrukcia má tendenciu vybočiť v tvare funkcie sinus, s počtom vĺn pri nevystuženej
konštrukcií - 64 polvĺn, pri horizontálne vystuženej konštrukcií 64 polvĺn. Pozoruhodná situácia nastáva pri porovnaní
nevystuženej konštrukcie s konštrukciou vystuženou horizontálnymi výstuhami, kde vystužená konštrukcia je
náchylnejšia na startu stability vybočením ako nevystužená. Pri nevystuženej konštrukcií je z tvaru vybočenia zrejmá
nižšia tuhosť konštrukcie. Konštrukcia sa deformuje vo väčšej oblasti ako pri konštrukcií vystuženej horizontálnymi
prstencami. Pri vystužení horizontálnymi výstuhami je oblasť deformácie v zásade obmedzená na oblasť „no. 3“ (pozri
Obr. 3). Pri platnosti podmienky pre maximálnu vzdialenosť priečnych rebier
trl ..10 [2] (3)
ktorá je v riešenom príade prekročená, nemajú priečne výstuhy vplyv na zvýšenie kritického napätia pri vydúvaní.
Vertikálne výstuhy majú na stabilitnú únosnosť významný vplyv. Aplikovaním vertikálnych výstuh bolo dosiahnuté
zvýšenie kritického napätia pri vydúvaní o cca. 75%.
Pri porovnaní konštrukcie vystuženej vertikálnymi rebrami s konštrukciou vystuženou ortogonálne zaujme nižšie
kritické napätie pri vydúvaní ortogonálne vystuženej konštrukcie ako pri konštrukcií vystuženej len vertikálnymi
výstuhami. Pri ortogonálne vystuženej konštrukcií dosiahne tvar amplitúda vybočenia len 40% z hodnoty pri vertikálne
vystuženej konštrukcií. Vydúvanie ortogonálne vystuženej konštrukcie má lokálny charakter, stena sila vybočí v oblasti
označenej ako „no. 3“ medzi vertikálnymi rebrami. Pri ortotropne vystuženej konštrukcií vybočila v tvare 80 polvĺn. Pri
konštrukcií vystuženej vertikálnymi rebrami valcová stena nadobudla deformovaný tvar po celej výške a obvode
konštrukcie. Dá sa odhadovať, že konštrukcia má malú pokritickú rezervu, konštrukcia vybočila globálne.
Pri výpočte metódou malých deformácií boli zistené len bifurkačné body, hodnoty kedy konštrukcia stratí stabilný tvar.
Pokritické správanie sa konštrukcie nie je možné opísať použitím metódy malých deformácií. Z tvarov vybočenia –
lokálneho je zrejmé, že ortogonálne vystužená konštrukcie má značné rezervy v pokritickom správaní sa a aj po
prvotnom – lokálnom vydutí by ostala stabilná.
Pre skúmanie pokritického správania sa konštrukcie je nutné použiť geometricky nelineárny výpočet použitím metódy
veľkých deformácií.
Pre ilustráciu boli v ďaľšom riešení načrtnuté tvary vybočenia nevystuženej valcovej škrupiny bez stužujúceho prstenca
na voľnom okraji konštrukcie. Norma EC 1993-1-6 nezohľadňuje takýto typ okrajových podmienok. Z tvarov straty
stability je zrejmé globálne vybočenie steny sila v 16 polvlnách šíriacich sa od voľného konca valcovej škrupiny.
Z tvaru vybočenia je zrejmé, že vertikálne rebrá by nemali zásadný vplyv na zvýšenie kritického napätia pri výdúvaní.
Obr. 15 Tvar straty stability, pôdorys, hladká
konštrukcia bez koncovej obruče
Obr. 16 Tvar straty stability, pohľad, hladká
konštrukcia bez koncovej obruče
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6
Tab. 3 Násobiteľe zaťaženia pri strate stability
1.4 Postupy pre výpočet meridiánnych napätí pri strate stability
Problematika riešenia škrupinových konštrukcií normovými výpočtovými postupmi je rozsiahla. Definuje
výpočtové postupy pre numerické riešenie napätosti škrupinových konštrukcií. Vplyv imperfekcií je zohľadnený vo
výpočte charakteristickej pevnosti pri vydúvaní parametrom c. Imperfekcie môžu byť geometrické (odchýlky od
ovality, excentricita – odsadenie v spoji, lokálne vydutie, odchýlka rovinnosti styku), alebo materiálové (nehomogénny
materiál, vplyv vnesených napätí zváraním).
V jednoduchosti sa dá napísať vzťah pre charaketistickú pevnosť pri vydúvaní ako
(4)
kde cx je súčiniteľ vydúvania v meridiánnom smere, sa určuje ako funkcia pomernej štíhlosti lpom.x
1x ak 0.. pomxpom
)(1
0..
0..
pomppom
pomxpom
x
ak ppomxpompom ..0.
2
.xpom
x
ak xpomppom ..
kde
1
.ppom
xRcr
yk
xpom
f
.
a redukčný faktor pružnej imperfekcie
b faktor rozsahu plastickej oblasti
h interakčný exponent
lpom.0 medzná pomerná štíhlosť pri úplnej pastizácií
lpom.p medzná plastická pomerná štíhlosť
Výpočet kritických napätí pri vydúvaní vychádza z lineárneho riešenia škrupín na základe vzťahu (1). Tento vzťah
je obmedzený na výpočet hladkých škrupinových konštrukcií s okrajovými podmienkami BC1, BC2 (votknutie, kĺbové
podopretie) [7].
(5)
Na vystihnutie geometrie škrupinovej konštrukcie zadáva parameter Cx závislý na pomere, ktorým zatrieďuje
konštrukciu medzi krátke, stredne dlhé a dlhé škrupiny.
(6)
Vyšetrovaná škrupina spadá do kategórie stredne dlhých škrupín (vplyv lokálneho zaťaženia odoznie v určitej
Násobiteľ hodnoty
zaťaženia pri
vydúvaní
Cylindrická škrupina, d = 36m, h = 41m, oceľ S275, hrúbka 10-29mm,
typ zaťaženia – osový tlak, LBA-MNA
Č. tvaru vybočenia Nevystužená bez stuž. prstenca
1 79,112
2 79,128
3 83,631
4 83,634
5 86,248
ykxRkx f..
r
t
CE xxRcr .605.0
tr
L
.
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2.2 Konstrukce kovové, dřevěné a kompozitní
7
vzdialenosti od pôsobiska, neovplyvňuje druhý okraj konštrukcie, konštrukcia sa neposudzuje ako tuhý prút) . Pre
stredne dlhé škrupiny vplyv okrajových podmienok vstupuje do výpočtu ako parameter Cx = 1. Ako vidno zo vzťahu
(1) hodnota kritického napätia pri vydúvaní je lineárne nepriamoúmerná štíhlosti škrupinovej konštrukcie. V praxi sú
časté prípady zmeny hrúbky škrupiny. Hrúbka nami vyšetrovaného sila sa mení od 10mm do 29mm.
Z výsledkov FEM analýzu bola zistená hodnota násobiteľa zaťaženia pri vydúvaní pre hladkú škrupinu s vystuženým
okrajom prstenom x = 93,539 (pre prvý tvar straty stability). Zaťaženie v kritickom mieste konštrukcie (Obr. 3 v poli
označenom ako „no.3“) bude mať hodnotu vypočítanú podľa vzťahu
(7)
ti hrúbka steny sila v i-tom mieste
hi výška oblasti s rovnakou hrúbkou ti
g tiažové zrýchlenie
r hustota ocele
x násobiteľ zaťaženia (x = 93,539)
potom kritické napätia pri vybočení majú hodnotu podľa vzťahu
mt
N
i
i
cr
1.
Výpočet FEM ANSYS Výpočet EC 1993-1-6
Kritické napätie pri vydúvaní [kN] 128,53 130,58
Tab. 3 Kritické napätie pri vydúvaní, výpočet podľa FEM a EC
Vzťahy pre výpočet kritického napätia pri vydúvaní vystužených škrupín norma EC 1993-1-6 neuvádza. V literatúre [2]
je uvádzaný vzťah pre kritické napätie pri vydúvaní, kde as je osová vzdialenosť vertikálnych výstuh.
(8)
Zároveň musí byť splnená podmienka, vzdialenosť rebier má byť menšia ako
(9)
inak je škrupina posudzovaná ako nevystužená. Z grafu nižšie sú badateľné rozdiely výpočtových vzťahov kritického
napätia pri vydúvaní pre vystužené a nevystužené škrupiny. Kritické napätie nevystuženej škrupiny rastie lineárne
s prevrátenou hodnotou štíhlosti (graf 1, červená čiara), pri vystuženej škrupine je kvadratická závislosť na pomere
hrúbky škrupinovej konštrukcie a vzdialenosť podpier (graf 1, zelená čiarkovaná čiara). Tento vzťah nezohľadňuje
kvalitatívne parametre výstuh, ich prierezové charakteristiky, iba vzájomnú vzdialenosť. Je pozoruhodné, že v hrúbkach
plechu konštrukcie menších ako cca. 18mm vychádzajú kritické napätia nižšie ako kritické napätie hladkej škrupiny.
Pre ilustráciu je uvedená aj charakteristická pevnosť pri vydúvaní vypočítaná pomocou vzťahov uvedených vyššie.
Graf 1 Kritických napätia pri vydúvaní
2
.. ).(6,3
s
Vcrx
a
t
E
tras ..4,4
xmghtN
i
i iii .1..)..(0
0.01 0.015 0.02 0.025
1 10
8
2 10
8
3 10
8
4 10
8
x.cr
x.Rk
x.cr.V
8. JUNIORSTAV 2011
2.2 Konstrukce kovové, dřevěné a kompozitní
8
1.5 Záver
V článku sú ukázané rôzne metódy na výpočet kritického napätia pri vydúvaní. Boli porovnané výsledky výpočtu
pre hladkú – nevystuženú škrupinu, z ktorých je zrejmá dobrá zhoda riešenia pomocou výpočtového programu FEM
ANSYS s výpočtovými postupmi uvedenými v EC 1993-1-6. Norma EC 1993-1-6 neudáva vzťahy na výpočet
kritického napätia pri vydúvaní pre vystužené škrupinové koštrukcie. Porovnanie výsledkov FEM ANSYS
nepreukázalo zhodu s riešením podľa vzťahu (8). Preto je odporúčané používať pri návrhu vystužených konštrukcií
výpočtové programy na báze metódy konečných prvkov. Pre ďaľšie a podrobnejšie skúmanie sa ukazuje lineárne
geometrická metóda ako nedostatočná. Nezohľadňuje pokritické správanie sa škrupinovej konštrukcie, čo najmä pri
ortotropne vystuženej škrupinovej konštrukcií sa ukazuje ako zavádzajúce a konštrukcie sú pri výpočte
predimenzované.
Zoznam použitej literatúry:
[1] Křupka, V., Schneider, P., Konstrukcie aparátu, PC-DIR, 1998, 290 str., ISBN 80-214-1124-4
[2] Křupka, V., Výpočet válcových tenkostěnných kovových nádob a potrubí, SNTL, 1967, 244str., Praha
[3] Gobratov, N., Valenta, J., Statika skořepin a skořepinových konstrukcí, SNTL, 1972, 575str. Praha
[4] STN EN 1991-1-1, Eurokód 1: Zaťaženie konštrukcií. Časť 1-1: Objemové hmotnosti, vlastná tiaž a úžitkové
zaťaženia, Slovenský ústav technickej normalizácie, 2004, 44 str.
[5] EN 1993-1-1, Eurokód 3: Design of steel structures. Part 1-1: General rules and rules for buildings, European
committee for standardisation, 2005, 94 str.
[6] STN EN 1993-1-5, Eurokód 3: Navrhovanie oceľových konštrukcií. Časť 1-5: Nosné stenové prvky, 2008, 56
str.
[7] STN EN 1993-1-6, Eurokód 3: Navrhovanie oceľových konštrukcií. Časť 1-6: Pevnosť a stabilita
škrupinových konštrukcií, 2007
[8] Agócs, Z., Brodniansky, J., Ároch, R., Slivanský, M.., Expertízne posúdenie technického stavu oceľových
konštrukcií slinkových síl PC1 a PC2. Návrh opatrení na zabezpečenie prevádzkovej spoľahlivosti a
bezpečnosti objektov posudzovaných síl v závode HOLCIM, Bratislava, SvF STU, 2006
[9] Ansys release 11.0, Documentation for ANSYS, Ansys, Inc. , 2007, USA
Recenzoval
Zoltán Agócs, prof. h.c, prof. Dr. Ing., PhD., agocs@ingsteel.sk