This document contains examples and problems related to geometric design and pavement design from a Winter 2008 CEE320 course. It includes problems on designing vertical curves for a highway overpass, determining superelevation for a curved raceway, evaluating a horizontal and vertical curve, and designing ramps and pavements. Design considerations include speed, grade, curvature, structure dimensions, and traffic loading.
Double lane change maneuver (rigid vehicle model and non predictive driver mo...saeid ghaffari
*Only the first five pages are presented here. If you are interested to study the rest of this project, feel free to contact me via saeid.ghaffari@studenti.polito.it.
This project is studying a double lane change maneuver according to ISO 3888 standard using a rigid vehicle model and non-predictive driver model. The vehicle speed is 80 km/h and the lane change should be followed without touching the lanes. Furthermore, the width of the lanes are given as a function of the vehicle width. A driver model is adopted which is represented by servomechanism having the yaw angle Ψ as input and the steering angle δ as output which is proportional to the error between the effective Ψ and the angle of the trajectory. The transfer function between the output δ and the input Ψ in the Laplace domain is given by the driver gain, the delay of the driver and the Laplace variable. Hence, the stability of the vehicle can be analysed plotting Root loci for different values of driver gain and driver delay. Side slip angle of the vehicle β, steering angle δ and yaw rate as a function of the time will be derived while the trajectory is plotted in XY plane.
Assessing the Aerodynamic Performance of a Formula SAE Model by means of CFD ...saeid ghaffari
A simplified race car model is used in this project to analyse the aerodynamic performance of a Formula SAE car by means of CFD simulation. First, the simulation workflow in Star-CCM+ will be demonstrated. Then, before applying volumetric controls and prism-layer mesh refinement to obtain more accurate results, tools to judge solution convergence are introduced.
*the first six pages of this project are presented here. If you are interested to study the rest of this document, please contact me via saeid.ghaffari@studenti.polito.it.
A Study on how Spot Welds Affect the Stiffness of a Car Body T-jointsaeid ghaffari
* only the first 6 pages of this project is presented here. If you are interested to study the rest of this document please contact me via saeid.ghaffari@studenti.polito.it.
With respect to the importance of the T-joint in a vehicle body strength, this project aims to study the joint torsional and bending stiffness in the two main directions. Furthermore, the influence of the number of spot welds on the stiffness of the joint will be analysed benefiting from Altair Hyperworks (Hypermesh FEA software).
Double lane change maneuver (rigid vehicle model and non predictive driver mo...saeid ghaffari
*Only the first five pages are presented here. If you are interested to study the rest of this project, feel free to contact me via saeid.ghaffari@studenti.polito.it.
This project is studying a double lane change maneuver according to ISO 3888 standard using a rigid vehicle model and non-predictive driver model. The vehicle speed is 80 km/h and the lane change should be followed without touching the lanes. Furthermore, the width of the lanes are given as a function of the vehicle width. A driver model is adopted which is represented by servomechanism having the yaw angle Ψ as input and the steering angle δ as output which is proportional to the error between the effective Ψ and the angle of the trajectory. The transfer function between the output δ and the input Ψ in the Laplace domain is given by the driver gain, the delay of the driver and the Laplace variable. Hence, the stability of the vehicle can be analysed plotting Root loci for different values of driver gain and driver delay. Side slip angle of the vehicle β, steering angle δ and yaw rate as a function of the time will be derived while the trajectory is plotted in XY plane.
Assessing the Aerodynamic Performance of a Formula SAE Model by means of CFD ...saeid ghaffari
A simplified race car model is used in this project to analyse the aerodynamic performance of a Formula SAE car by means of CFD simulation. First, the simulation workflow in Star-CCM+ will be demonstrated. Then, before applying volumetric controls and prism-layer mesh refinement to obtain more accurate results, tools to judge solution convergence are introduced.
*the first six pages of this project are presented here. If you are interested to study the rest of this document, please contact me via saeid.ghaffari@studenti.polito.it.
A Study on how Spot Welds Affect the Stiffness of a Car Body T-jointsaeid ghaffari
* only the first 6 pages of this project is presented here. If you are interested to study the rest of this document please contact me via saeid.ghaffari@studenti.polito.it.
With respect to the importance of the T-joint in a vehicle body strength, this project aims to study the joint torsional and bending stiffness in the two main directions. Furthermore, the influence of the number of spot welds on the stiffness of the joint will be analysed benefiting from Altair Hyperworks (Hypermesh FEA software).
Simulation and Static Analysis of an Off-Road Vehicle Roll CageIJMER
The SAE-BAJA competition is arranged every year with a purpose to have teams of
engineering students design, build and race a prototype of a four-wheel, one passenger, off-road
vehicle. The most important aspect of the vehicle design is the frame. The frame contains the operator,
engine, brake system, fuel system and steering mechanism, it must be of adequate strength to protect
the operator in the event of a rollover or impact. The roll cage must be constructed of steel tubing, with
minimum dimensional and strength requirements dictated by Society of Automotive Engineers (SAE).
Increased concern about the roll cage has created the importance of simulation and analysis thereby
predicting failure modes of the frame. In the present paper, we have used ANSYS to investigate the
response of the frame under various impacts. We considered a direct frontal impact and side impact
that results in a 4g horizontal loading, a rollover impact of 3g deceleration value, bump impact and
front torsional impact analysis with 3g deceleration value. The impact loading is simulated by
restricting displacements at certain locations, and applying discrete forces at various points on the
frame where the weight is concentrated. Throughout the analysis of roll cage more emphasis was given
on obtaining a allowable factor of safety and designed according to it.
Precision 3D inspection & analysis of a single belt oven conveyor system to include the following components: drive and tension drum, oven, framework, guide rails & guide rollers.
Vibration analysis of Drivelines using MBD and the ability of the solvers is showcased in this ppt.
Consideration of 1D, 2D and 3D MBD models for drivelines and performing order analysis for the same.
Result shows the MBD capability of driveline simulations.
Simulation and Static Analysis of an Off-Road Vehicle Roll CageIJMER
The SAE-BAJA competition is arranged every year with a purpose to have teams of
engineering students design, build and race a prototype of a four-wheel, one passenger, off-road
vehicle. The most important aspect of the vehicle design is the frame. The frame contains the operator,
engine, brake system, fuel system and steering mechanism, it must be of adequate strength to protect
the operator in the event of a rollover or impact. The roll cage must be constructed of steel tubing, with
minimum dimensional and strength requirements dictated by Society of Automotive Engineers (SAE).
Increased concern about the roll cage has created the importance of simulation and analysis thereby
predicting failure modes of the frame. In the present paper, we have used ANSYS to investigate the
response of the frame under various impacts. We considered a direct frontal impact and side impact
that results in a 4g horizontal loading, a rollover impact of 3g deceleration value, bump impact and
front torsional impact analysis with 3g deceleration value. The impact loading is simulated by
restricting displacements at certain locations, and applying discrete forces at various points on the
frame where the weight is concentrated. Throughout the analysis of roll cage more emphasis was given
on obtaining a allowable factor of safety and designed according to it.
Precision 3D inspection & analysis of a single belt oven conveyor system to include the following components: drive and tension drum, oven, framework, guide rails & guide rollers.
Vibration analysis of Drivelines using MBD and the ability of the solvers is showcased in this ppt.
Consideration of 1D, 2D and 3D MBD models for drivelines and performing order analysis for the same.
Result shows the MBD capability of driveline simulations.
Alternative Approach to Permanent way Alignment DesignConstantin Ciobanu
The speaker presented a comparison between the Track
alignment design approach based on NR standards and the one based on the European Norms and the Technical Specifications for Interoperability (TSI), highlighting the main area where these approaches are different and touching the subject of the safety design factors embedded in the track alignment design
procedures.
The main topics:
Cant parameters definition, the origin of the 11.82 cant constant. ways of applying cant.
Track geometry recording. Quality Standard deviation. Inherent standard deviation. The advantage of using rolling SDs. Quality bands for low and high speed.
Cant over a reverse transition - the orphan rule of lifting the reversing point to improve the quality of riding.
Designing a sudden change in curvature. Virtual transition - TRK2049. The rules of the European Norm for track geometry EN 13803-1&2
The significance of transition shift.
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
2. CEE320
Winter2008
Problem 3.15
Due to crashes at a railroad crossing, an overpass (with a surface 24 ft
above the existing road) is to be constructed on an existing level
highway. The existing highway has a design speed of 50 mph. The
overpass structure is to be level, centered above the railroad, and 200
ft long. What length of the existing level highway must be
reconstructed to provide an appropriate vertical alignment?
3.
4. CEE320
Winter2008
Problem 3.27
A developer is having a single-lane raceway constructed with a 100
mph design speed. A curve on the raceway has a radius of 1000 ft, a
central angle of 30 degrees, and PI stationing at 1125+10. If the
design coefficient of side friction is 0.20, determine the superelevation
required at design speed (do not ignore the normal component of the
centripetal force). Also, compute the degree of curve, length of curve,
and stationing of the PC and PT.
5.
6. CEE320
Winter2008
Geometric Design Example
A 2-lane (10 ft wide lanes) combined horizontal and crest vertical curve
is currently posted for a 35 mph speed limit and is designed for 40 mph.
Curve data are:
•Horizontal: L = 580 ft, Δ = 60°, e = 6%, Ms = 30 ft
•Vertical: L = 580 ft, G1 = 3%, G2 = -2.5%
Is this curve adequately designed for 40 mph?
Because this curve is often covered in packed snow and ice, the county
wants to post a recommended speed limit for these conditions. What
speed limit do you recommend?
7. CEE320
Winter2008
Problem 3.37
Two straight sections of freeway cross at a right angle. At the point of crossing, the east-
west highway is at elevation 150 ft and is a constant +5.0% grade (upgrade in the
east direction), the north-south highway is at elevation 125 ft and is a constant -3.0%
grade (downgrade in the north direction). Design a 90-degree ramp that connects the
northbound direction of travel to the eastbound direction of travel.
Design the ramp for the highest design speed (to the nearest 5 mph) without exceeding a
minimum D of 8.0. (Assume the PC of the horizontal curve is at station 15+00, and
the vertical curve PVIs are at the PC and PT of the horizontal curve). Maximum
allowed superelevation by design standards is 12%.
Determine the following:
1. Stationing and elevations of the horizontal curve PC and PT
2. Horizontal curve radius and length
3. Stationing and elevations of the vertical curve PVCs and PVTs
4. Vertical curve lengths
5. Length of constant grade in between the 2 vertical curves (if any)
11. CEE320
Winter2008
Pavement Design Example
The pavement on Stevens way is slowly being switched to PCC a few
thousand yards at a time. Assuming all the heavy vehicle traffic on
Stevens Way is due to bus traffic, estimate a rigid pavement design
using the following data:
•Design life = 40 years
•Articulated bus average axle weights:
•Front = 15,000 lb
•Middle = 18,500 lb
•Rear = 11,500 lb
•Regular (non-articulated) bus average axle weights:
•Front = 12,200 lb
•Rear = 20,000 lb
•Typical school day = 80 regular, 40 articulated in one direction
•Bus traffic growth rate = 2% per year
•Use undowel joints and crushed stone base material
Find K values for the crest and sag vertical curve.
Ksag = 96 for 50 mph
Kcrest = 84 for 50 mph
Because the combination sag & crest curve goes between two flat grades:
G1 for the sag = 0
G2 for the sag = G1 for the crest
G2 for the crest = 0
Therefore, A for the crest = A for the sag
Use L = LA to express length in terms of K. We know that A is the same for both because A = G2 – G1 and
Lsag = 96A
Lcrest = 84A
Use a vertical relationship to get the second equation:
AL/200 = Yf = AL/200
Therefore, ALsag/200 + ALcrest/200 = 24 ft
Substitute and solve for A
A(96A)/200 + A(84A)/200 = 24
A = 5.16% = G2 for the sag = G1 for the crest
Find curve lengths
Lsag = KsagA = (96)(5.16) = 495.36 ft.
Lcrest = KcrestA = (84)(5.16) = 433.44 ft
Find total length of highway that must be reconstructed
Need one sag and one crest curve on each end = 2(495.36) + 2(433.44) = 1857.6 ft
Add the 200 ft long flat section at the top = 1857.6 + 200 = 2057.6 ft.
The proper equation is equation 3.33
tan(α) + fs = (V2/gRv)(1 – fstan(α))
Although In the typical formula the fstan(α) term is ignored because it is small, this is the normal component of the centripetal acceleration and will not be ignored here.
Solve for α
tan(α) + 0.20 = ((100 x 1.47)2/(32.2)(1000))(1 – 0.20tan(α)
tan(α) + 0.20 = 0.671(1 – 0.20tan(α)
tan(α) + 0.20 = 0.671 – 0.1342tan(α)
1.1342 tan(α) = 0.471
tan(α) = 0.4153
α = 22.55°
e = 41.53
If we ignored the normal component of centripetal acceleration, e = 47.11
As we get into big superelevations then it is no longer practical to ignore the normal component
Degree of curvature
(π/180)RΔ = 100Δ/D
D = 5.73
Curve length
L = 100Δ/D = 523.56 ft
Stationing
T = Rtan(Δ/2) = 267.95 ft
PC = PI - T = 112510 – 267.95 = 1122+42.05
PT = PC + L
PT = 112510 + 523.56 = 1130+33.56
Determine if horizontal curve is adequate for 40 mph
R = 180L/πΔ = 553.9 ft (this is the centerline radius)
Rv = centerline radius – 5 ft = 548.9 ft
Rv = V2/(g(fs + e))
Use limiting value of fs from Table 3.5 = 0.150
V = 60.9 ft/s = 41.44 mph
OK
Determine adequacy of vertical curve
K = L/A = 580/(3 - -2.5) = 105.5
From Table 3.2, K = 44 for 40 mph
OK
What is the available SSD?
Horizontal curve: SSD = (πRv/90)(cos-1((Rv – Ms)/Rv))
SSD = (19.16)cos-1(0.9453)
SSD = 364.6 ft
This SSD consists of braking distance + reaction time (2.5 x initial speed)
Vertical curve (assume SSD < L):
SSD2 = 2158L/A = 2158(580)/5.5 = 227,571
SSD = 477 ft
Therefore, horizontal is more limiting and SSDavailable = 364.6 ft
On packed snow and ice the braking distance will be much greater due to reduced friction
S (braking distance ignoring aerodynamic resistance) = γb(V2)/(2g(ηbμ + frl +/- sinθ)
Assumptions
Mass factor = 1.04
Braking efficiency = 0.80 (can’t really assume ABS at this juncture)
Coefficient of road adhesion from Table 2.4 = 0.10
Grade = assume 0, since part will be uphill and part will be downhill
S = (1.04)(V2)/(2(32.2)((0.80)(0.10)+0.01(1+V/294) + 0))
S = 0.0161V2/(0.08 + 0.01 + V/29400)
S = 0.0161V2/(0.09 + V/29400)
Calculate stopping sight distance
SSD = reaction time + braking distance
SSD = 2.5(V) + 0.0161V2/(0.09 + V/29400) = 364.6
32.81 + 0.0124V = 0.225V + 0.000085V2 + 0.0161V2
0 = 0.01619V2 + 0.2126V – 32.81
V = 38.93 or -52.06
V = 38.93 ft/s = 26.48 mph
Check SSD
SSD = 2.5(38.93) + (1.04)(38.932)/(2(32.2)((0.80)(0.10)+0.01(1+38.93/294) + 0))
SSD = 97.3 + 268.0 = 365.3 ft
OK
Recommended speed limit could be posted at 25 mph or even 20 mph
Convert each type of bus to an ESAL (use 4th power law as approximation)
Articulated = 0.4823 + 1.1158 + 0.1667 = 1.7647
Regular = 0.211 + 1.52 = 1.7352
Calculate total ESALs per day
1.7647(40) + 1.7352(80) = 209 ESALs/day
Calculate total lifetime ESAL loading
ESALs per day during the school year is probably much higher than not during
Assuming ESAL loading is about half during the summer and during weekends
Assume summer = 3 months = 100 days
Assume school year = 265 days (of which about 80 are weekends/holidays)
ESALs = (185)(209) + (80 + 100)(209/2) = 57,475/year
Grow the ESALs over 40 years from present year
Total ESALs = (57,475)((1 + 0.02)40 – 1)/0.02 = 57,475(60.40) = 3,471,604 ESALs
Use WSDOT Table to determine PCC design
Need to select a reliability (might want to use a high one since it is a highly visible road)
If reliability = 75% then design is 9” PCC over 4” or 6” of base course
If reliability = 85% then design is 9.5” PCC over 4” or 6” of base course
If reliability = 95% then design is 10.5” PCC over 4” or 6” of base course
Grow the ESALs over 40 years from present year
Total ESALs = (57,475)((1 + 0.02)40 – 1)/0.02 = 57,475(60.40) = 3,471,604 ESALs
Use WSDOT Table to determine flexible design
Need to select a reliability (might want to use a high one since it is a highly visible road)
If reliability = 75% then design is 8” HMA over 4” of base course
If reliability = 85% then design is 8.5” HMA over 4” of base course
If reliability = 95% then design is 10.0” HMA over 4” of base course
Keep in mind the WSDOT assumptions in the table
Note that pavement depths of HMA and PCC are quite similar
Mention that ESALs for rigid and flexible pavement are not the same but it is okay for the broad assumptions of this example