The document discusses the need for nonlinear soil-structure interaction (NLSSI) analysis in seismic probabilistic risk assessment of nuclear power plants. NLSSI analysis can better model structural behavior during large earthquakes by capturing effects like gapping and sliding not seen in linear analysis. The document outlines a project to develop NLSSI methods and tools to reduce uncertainties in seismic risk calculation. It describes performing probabilistic response analysis using both linear and NLSSI models of a nuclear power plant and soil properties and comparing the results.
The document describes the ZEB1 mobile laser scanner for mining applications. It can be used for tasks like underground mine mapping, roof support bolt inspection, accurate volume calculations, clash detection, and change monitoring. The ZEB1 captures 3D scan data that is uploaded and processed into a point cloud and 3D model. Examples show it being used to scan underground tunnels, mine shafts, and stockpiles. When combined with the ZebRA remote actuator, it can perform autonomous scans. Case studies demonstrate its use at a coal mine and copper mine for applications like tunnel profiling and comparison to total station surveys.
ZEB1 is an innovative handheld mobile mapping system - which creates an accurate 3D point clouds without the need for GPS. This makes it ideal for buildings, mines and caves.
Presented by Henno Morkel
First shown: Tuesday 29th September 2015
How Do You Measure Your Building Interior?
Topics: Find out why chartered surveyors around the world are adopting this game changing technology from the ZEB1.
Nonlinear Aeroelastic Steady Simulation Applied to Highly Flexible Blades for...Fausto Gill Di Vincenzo
A novel approach is presented to perform nonlinear aeroelastic steady-state simulations of highly flexible structures such as fix wings and rotating blades. The methodology has been developed in a specific OpenFSI service available in MSC Nastran SOL 400 that
includes follower forces and incremental loads features to allow for accurate nonlinear steady Fluid-Structure Interaction analysis. The new service, called HSA.OpenFSI, based on the HSA Toolkit, has been implemented to couple MSC Nastran to a CFD solver. Six DOF spline technology is used to interpolate data between the aerodynamic and structural grids. A new approach has been designed to improve the efficiency of this technology that allows to considerably reduce the time needed to create the interpolation spline matrix and the disk space to store it. A Nastran-based FEM algorithm has been developed to take care of the fluid domain deformation. The proposed approach has been validated on a flap in a duct model, where transient steady-state results are available from other approaches, and then preliminary results on a proprotor two-blade model of Micro Air Vehicles MAV from ISAE will be presented.
Ph.D. Thesis project of Paolo E. Sebastiani PBEE - Mala Rijeka ViaductFranco Bontempi
The case study bridge "Mala Rijeka" is one of the most important bridges on the Belgrade - Bar International Line. The bridge was built in 1973 as the highest railway bridge in the World (Worlds Record Lists) and it is a continuous fivespan steel frame carried by six piers of which the middle ones have heights ranging from 50 to 137.5 m measured from the foundation interface. The main steel truss bridge structure consists in a continuous girder with a total length L=498.80 m. Static truss height is 12.50 m, and the main beams are not parallel, but are radially spread, in order to adjust to the route line.
Performance-based earthquake engineering (PBEE) consists of the evaluation, design and construction of structures to meet seismic performance objectives (expressed in terms of repair costs, downtime, and casualties) that are specified by stakeholders (owners, society, etc.).
It is based on the premise that performance can be predicted and evaluated with quantifiable confidence to make, together with the client, intelligent and informed trade-offs based on life-cycle considerations rather than
construction costs alone.
Multi-objective optimization for the probabilistic seismic performance based design of an example moment frame steel structure is presented. Direct economic and social losses associated with seismic events, which are of interest in the current recommended frameworks for the performance based design of structures, are considered in the optimization problem defined. Three optimization objectives are selected: the initial construction cost, modeled as the weight of the structural system; expected annual economic loss associated with damage resulting from seismic hazard; and expected annual social loss resulting from seismic hazard induced damage. Hazus recommended procedures are applied in the economic and social loss calculations which include the fragility functions used in the damage analyses and injury event models implemented in the social loss calculations. The multiobjective optimization method uses a non-dominated sorting genetic algorithm strategy. The optimization results for the multiple objectives are presented and discussed in the form of Pareto fronts. Engineering demand parameters implemented for the seismic loss analysis are inter-story drifts and peak floor accelerations and are obtained using inelastic time history analysis for the ground motions associated with various seismic hazard levels. To illustrate the design procedure, loss parameters are calculated for an example steel structure located in Los Angeles, CA.
The document describes the ZEB1 mobile laser scanner for mining applications. It can be used for tasks like underground mine mapping, roof support bolt inspection, accurate volume calculations, clash detection, and change monitoring. The ZEB1 captures 3D scan data that is uploaded and processed into a point cloud and 3D model. Examples show it being used to scan underground tunnels, mine shafts, and stockpiles. When combined with the ZebRA remote actuator, it can perform autonomous scans. Case studies demonstrate its use at a coal mine and copper mine for applications like tunnel profiling and comparison to total station surveys.
ZEB1 is an innovative handheld mobile mapping system - which creates an accurate 3D point clouds without the need for GPS. This makes it ideal for buildings, mines and caves.
Presented by Henno Morkel
First shown: Tuesday 29th September 2015
How Do You Measure Your Building Interior?
Topics: Find out why chartered surveyors around the world are adopting this game changing technology from the ZEB1.
Nonlinear Aeroelastic Steady Simulation Applied to Highly Flexible Blades for...Fausto Gill Di Vincenzo
A novel approach is presented to perform nonlinear aeroelastic steady-state simulations of highly flexible structures such as fix wings and rotating blades. The methodology has been developed in a specific OpenFSI service available in MSC Nastran SOL 400 that
includes follower forces and incremental loads features to allow for accurate nonlinear steady Fluid-Structure Interaction analysis. The new service, called HSA.OpenFSI, based on the HSA Toolkit, has been implemented to couple MSC Nastran to a CFD solver. Six DOF spline technology is used to interpolate data between the aerodynamic and structural grids. A new approach has been designed to improve the efficiency of this technology that allows to considerably reduce the time needed to create the interpolation spline matrix and the disk space to store it. A Nastran-based FEM algorithm has been developed to take care of the fluid domain deformation. The proposed approach has been validated on a flap in a duct model, where transient steady-state results are available from other approaches, and then preliminary results on a proprotor two-blade model of Micro Air Vehicles MAV from ISAE will be presented.
Ph.D. Thesis project of Paolo E. Sebastiani PBEE - Mala Rijeka ViaductFranco Bontempi
The case study bridge "Mala Rijeka" is one of the most important bridges on the Belgrade - Bar International Line. The bridge was built in 1973 as the highest railway bridge in the World (Worlds Record Lists) and it is a continuous fivespan steel frame carried by six piers of which the middle ones have heights ranging from 50 to 137.5 m measured from the foundation interface. The main steel truss bridge structure consists in a continuous girder with a total length L=498.80 m. Static truss height is 12.50 m, and the main beams are not parallel, but are radially spread, in order to adjust to the route line.
Performance-based earthquake engineering (PBEE) consists of the evaluation, design and construction of structures to meet seismic performance objectives (expressed in terms of repair costs, downtime, and casualties) that are specified by stakeholders (owners, society, etc.).
It is based on the premise that performance can be predicted and evaluated with quantifiable confidence to make, together with the client, intelligent and informed trade-offs based on life-cycle considerations rather than
construction costs alone.
Multi-objective optimization for the probabilistic seismic performance based design of an example moment frame steel structure is presented. Direct economic and social losses associated with seismic events, which are of interest in the current recommended frameworks for the performance based design of structures, are considered in the optimization problem defined. Three optimization objectives are selected: the initial construction cost, modeled as the weight of the structural system; expected annual economic loss associated with damage resulting from seismic hazard; and expected annual social loss resulting from seismic hazard induced damage. Hazus recommended procedures are applied in the economic and social loss calculations which include the fragility functions used in the damage analyses and injury event models implemented in the social loss calculations. The multiobjective optimization method uses a non-dominated sorting genetic algorithm strategy. The optimization results for the multiple objectives are presented and discussed in the form of Pareto fronts. Engineering demand parameters implemented for the seismic loss analysis are inter-story drifts and peak floor accelerations and are obtained using inelastic time history analysis for the ground motions associated with various seismic hazard levels. To illustrate the design procedure, loss parameters are calculated for an example steel structure located in Los Angeles, CA.
Multiphase Flow Modeling and Simulation: HPC-Enabled Capabilities Today and T...inside-BigData.com
In this video from the 2014 HPC User Forum in Seattle, Igor Bolotnov from North Carolina State University presents: Multiphase Flow Modeling and Simulation: HPC-Enabled Capabilities Today and Tomorrow.
Learn more: http://insidehpc.com/video-gallery-hpc-user-forum-2014-seattle/
Part-II: Seismic Analysis/Design of Multi-storied RC Buildings using STAAD.Pr...Rahul Leslie
For novice, please continue from "Modelling Building Frame with STAAD.Pro & ETABS" (http://www.slideshare.net/rahulleslie/modelling-building-frame-with-staadpro-etabs-rahul-leslie).
This is a presentation covering almost all aspects of Seismic analysis & design of Multi-storied RC Structures using the Indian code IS:1893-2016 (New edition), with references to IS:13920-2015 (Code for ductile detailing) & IS:16700-2017 (code for design of tall buildings) where relevant; following for each aspect of the code, (1) The clause/formula (2) It's explanation/theory (3) How it is/can be implemented in the software packages of (i) STAAD.Pro and (ii) ETABS
This is the latest edition of the earlier slides based on IS:1893-2002 which this one supersedes. This is Part-II of a two part series.
This document discusses pushover analysis, which is an inelastic static analysis method used to evaluate seismic performance of structures. It begins by outlining the target performance levels dictated by codes, then provides an overview of current analysis methods and their limitations. Next, it describes the steps of a pushover analysis in detail, including defining member behavior, applying loads, specifying the load pattern, and incrementally forming plastic hinges. An example application to a 3-story frame structure is presented to demonstrate the process. The document concludes by emphasizing pushover analysis as a practical alternative to time history analysis for estimating seismic response.
Seismic Instrumentation of Structures: What Have We Learned? - Mehmet ÇelebiEERI
Seismic instrumentation of structures has provided three key learnings:
1. Tall buildings far from earthquake epicenters can experience significant drift ratios from long-period ground motions. Data from two tall buildings in Japan showed this.
2. Structural modification features like base isolation and dampers have proven effective at reducing accelerations and displacements. Data from base-isolated buildings in the US and Japan supported this.
3. Drift ratio limits in building codes may need reevaluation given the drifts experienced by instrumented tall buildings under small ground motions. Code limits vary between countries and observed drifts have exceeded some.
Efficient analytical and hybrid simulations using OpenSeesopenseesdays
The document discusses efficient analytical and hybrid simulations using OpenSees. It describes overcoming convergence challenges in analytical simulation through evaluating time integrators and solution algorithms. A Lyapunov-based nonlinear solution algorithm is developed for improved convergence. Direct element removal is discussed for progressive collapse simulation. Hybrid simulation applications to wind turbine blades and curtain wall systems are also mentioned.
PUSHOVER ANALYSIS BASED ASSESSMENT OF SMART STRUCTURES SUBJECTED TO EXTERNAL ...Sardasht S. Weli
Illustrating the Modified Non-linear Static Analysis methods to assess the smart structures subjected to intentional blast loading.
This study numerically evaluates the robustness of the Nickle Titanium Shape Memory Alloy (NiTi SMA) as smart connection under external blast loading
This document summarizes a lecture on file systems and performance. It discusses the read/write process for magnetic disks involving seek time, rotational latency, and transfer time. Typical numbers for these parameters in magnetic disks are provided. Flash/SSD memory is also discussed as an alternative storage technology with advantages like low latency, no moving parts, and high throughput but also drawbacks like limited endurance. The document introduces concepts from queueing theory that can help analyze the performance of I/O systems, like modeling request arrival and service times as probabilistic distributions. Key metrics like response time and throughput are discussed for evaluating I/O performance.
This document presents a method for downsampling point cloud data to enable real-time scan matching for autonomous vehicles. It introduces two new downsampling algorithms: Ring Random Filter and Distance Voxel Grid Filter. It evaluates the algorithms based on execution time of scan matching, downsampling time, and relative error compared to raw point cloud data from tests in suburban and city environments. The results show the downsampling enables real-time scan matching with relative errors generally less than 10 cm.
Elastic response spectra are used to estimate the response of linear structures to earthquakes. They plot the peak response of oscillators with varying natural frequencies forced by the same ground motion. Site-specific spectra are developed using recorded ground motions for a site and account for local soil conditions, while code-based spectra provide a standardized approximation. Response spectra are useful for elastic design but have limitations for nonlinear or multi-mode systems.
Kinematic Mounting Scheme of Miniature Precision Elements for Mission Surviva...Ankit Sarvaiya
This document describes the design of a kinematic mount for precision optical elements on spacecraft to withstand environmental loads. It discusses the need for such a mount, prior work, the design process, and analysis. The design process involves identifying requirements, synthesizing options using flexures, analyzing mounts under different loads using FEA, and evaluating performance. Two mount designs are analyzed in detail and shown to withstand inertial loads up to 200g, temperature changes of 40°C, and vibrations within specified levels through stress/response analyses and experimental validation.
Low-power Innovative techniques for Wearable ComputingOmar Elshal
A presentation i did for the Ubiquitous and Wearable Computing seminar during my senior year in university.
The presentation introduces many research papers on the field then discusses one of them thoroughly.
The presentation describes how to integrate Laser Scan Data into FEA Model and Perform Level 3 Fitness-for-Service Assessment of Critical Assets in Refinery & Process Industries. It also, talks about an engineer friendly plugin that helps in the data import with insights from the asset owners and FEA consultants.
IMU (inertial measurement unit) has already played significant roles in the control system of aerospace and other vehicle platforms. Due to the maturity and low cost of MEMS technology, IMU starts to penetrate consumer products such as smartphone, wearables and VR/AR devices.
This sharing will focus on the general introduction of IMU components, signal characteristics and application concepts, with an attempt to guide those who is interested in the IMU-based system integration and algorithm development.
Boundary Conditions for Seismic Imaging: Computational and Geophysical Point...EssamAlgizawy
Reverse Time Migration (RTM) is a powerful seismic imaging approach, widely used for migrating areas of complex structures of steep-dips and subsalt regions, despite its high computational cost. Advancing wave-field in time represents the main cost of the RTM as it is usually done by using Finite Difference (FD) to solve the wave-equation. Accuracy of the solution is subject to the approximation of the FD in both time and space.
Theoretically, waves propagate their extends to infinity or continue until vanishing. Unfortunately, this is not applicable in modelling a particular region since we truncate model to a computational grid modelling a region of interest. Absorbing all incoming energy at the boundaries of the computational grid mimics a real-life infinite media. Many approaches attempt to mimic different kinds of absorbing boundary conditions (ABC) e.g. Sponge, PML, random boundaries, etc. The objective of this study is to find the best compromise between geophysical and computational standpoint, and find the best quality of the attenuation with a minimum number of additional grid points.
We review 2 RTM implementations; the first one is using the standard approach (2 propagation with in-memory snapshots of the full wave-field with IPP compression) covering Sponge and CPML boundary conditions, while the second implementation uses random velocity boundaries that almost avoids IO but involves an extra propagation. Thereof we can balance the number of grid points in the damping area to find the best combination with respect to the computational efficiency of the RTM kernels.
This document discusses engineering change orders (ECOs) used to fix timing, functional, power, and clock issues after physical design and sign-off. It describes the motivation for ECOs due to tool limitations and differences between implementation and sign-off. Common ECO techniques are listed for timing (driver upsizing, buffer insertion, etc.), power (vt-swapping, downsizing, etc.), and metal-only ECOs. Timing ECO tools from Synopsys, Cadence, and other vendors are also mentioned. Upcoming ECO technologies like dynamic power optimization and automatic legalization are noted.
This document presents a method for assigning tasks to cores in a heterogeneous multi-core system on chip (MCSOC) to minimize energy consumption. It uses a simulated annealing algorithm to iteratively search for mappings that reduce energy usage. The algorithm was tested on an MCSOC model with ARM Cortex-A7 and A15 cores using benchmark tasks run in Gem5 simulations. Results show the algorithm can reduce energy consumption by up to 70% compared to a non-optimized mapping approach, with greater reductions seen at higher numbers of iterations. Runtimes for the algorithm range from under a second to over 4 minutes depending on the problem size and number of iterations.
This document discusses limitations of traditional serial scan design for testing integrated circuits and proposes an alternative called Random Access Scan (RAS). RAS addresses three key limitations of serial scan: 1) test data volume, 2) test application time, and 3) test power. In RAS, flip-flops act as addressable memory elements during test mode, reducing time to set and observe flip-flop states compared to serial scan. While RAS requires more gates and test pins than serial scan, it significantly reduces switching activity and power consumption during testing.
Multiphase Flow Modeling and Simulation: HPC-Enabled Capabilities Today and T...inside-BigData.com
In this video from the 2014 HPC User Forum in Seattle, Igor Bolotnov from North Carolina State University presents: Multiphase Flow Modeling and Simulation: HPC-Enabled Capabilities Today and Tomorrow.
Learn more: http://insidehpc.com/video-gallery-hpc-user-forum-2014-seattle/
Part-II: Seismic Analysis/Design of Multi-storied RC Buildings using STAAD.Pr...Rahul Leslie
For novice, please continue from "Modelling Building Frame with STAAD.Pro & ETABS" (http://www.slideshare.net/rahulleslie/modelling-building-frame-with-staadpro-etabs-rahul-leslie).
This is a presentation covering almost all aspects of Seismic analysis & design of Multi-storied RC Structures using the Indian code IS:1893-2016 (New edition), with references to IS:13920-2015 (Code for ductile detailing) & IS:16700-2017 (code for design of tall buildings) where relevant; following for each aspect of the code, (1) The clause/formula (2) It's explanation/theory (3) How it is/can be implemented in the software packages of (i) STAAD.Pro and (ii) ETABS
This is the latest edition of the earlier slides based on IS:1893-2002 which this one supersedes. This is Part-II of a two part series.
This document discusses pushover analysis, which is an inelastic static analysis method used to evaluate seismic performance of structures. It begins by outlining the target performance levels dictated by codes, then provides an overview of current analysis methods and their limitations. Next, it describes the steps of a pushover analysis in detail, including defining member behavior, applying loads, specifying the load pattern, and incrementally forming plastic hinges. An example application to a 3-story frame structure is presented to demonstrate the process. The document concludes by emphasizing pushover analysis as a practical alternative to time history analysis for estimating seismic response.
Seismic Instrumentation of Structures: What Have We Learned? - Mehmet ÇelebiEERI
Seismic instrumentation of structures has provided three key learnings:
1. Tall buildings far from earthquake epicenters can experience significant drift ratios from long-period ground motions. Data from two tall buildings in Japan showed this.
2. Structural modification features like base isolation and dampers have proven effective at reducing accelerations and displacements. Data from base-isolated buildings in the US and Japan supported this.
3. Drift ratio limits in building codes may need reevaluation given the drifts experienced by instrumented tall buildings under small ground motions. Code limits vary between countries and observed drifts have exceeded some.
Efficient analytical and hybrid simulations using OpenSeesopenseesdays
The document discusses efficient analytical and hybrid simulations using OpenSees. It describes overcoming convergence challenges in analytical simulation through evaluating time integrators and solution algorithms. A Lyapunov-based nonlinear solution algorithm is developed for improved convergence. Direct element removal is discussed for progressive collapse simulation. Hybrid simulation applications to wind turbine blades and curtain wall systems are also mentioned.
PUSHOVER ANALYSIS BASED ASSESSMENT OF SMART STRUCTURES SUBJECTED TO EXTERNAL ...Sardasht S. Weli
Illustrating the Modified Non-linear Static Analysis methods to assess the smart structures subjected to intentional blast loading.
This study numerically evaluates the robustness of the Nickle Titanium Shape Memory Alloy (NiTi SMA) as smart connection under external blast loading
This document summarizes a lecture on file systems and performance. It discusses the read/write process for magnetic disks involving seek time, rotational latency, and transfer time. Typical numbers for these parameters in magnetic disks are provided. Flash/SSD memory is also discussed as an alternative storage technology with advantages like low latency, no moving parts, and high throughput but also drawbacks like limited endurance. The document introduces concepts from queueing theory that can help analyze the performance of I/O systems, like modeling request arrival and service times as probabilistic distributions. Key metrics like response time and throughput are discussed for evaluating I/O performance.
This document presents a method for downsampling point cloud data to enable real-time scan matching for autonomous vehicles. It introduces two new downsampling algorithms: Ring Random Filter and Distance Voxel Grid Filter. It evaluates the algorithms based on execution time of scan matching, downsampling time, and relative error compared to raw point cloud data from tests in suburban and city environments. The results show the downsampling enables real-time scan matching with relative errors generally less than 10 cm.
Elastic response spectra are used to estimate the response of linear structures to earthquakes. They plot the peak response of oscillators with varying natural frequencies forced by the same ground motion. Site-specific spectra are developed using recorded ground motions for a site and account for local soil conditions, while code-based spectra provide a standardized approximation. Response spectra are useful for elastic design but have limitations for nonlinear or multi-mode systems.
Kinematic Mounting Scheme of Miniature Precision Elements for Mission Surviva...Ankit Sarvaiya
This document describes the design of a kinematic mount for precision optical elements on spacecraft to withstand environmental loads. It discusses the need for such a mount, prior work, the design process, and analysis. The design process involves identifying requirements, synthesizing options using flexures, analyzing mounts under different loads using FEA, and evaluating performance. Two mount designs are analyzed in detail and shown to withstand inertial loads up to 200g, temperature changes of 40°C, and vibrations within specified levels through stress/response analyses and experimental validation.
Low-power Innovative techniques for Wearable ComputingOmar Elshal
A presentation i did for the Ubiquitous and Wearable Computing seminar during my senior year in university.
The presentation introduces many research papers on the field then discusses one of them thoroughly.
The presentation describes how to integrate Laser Scan Data into FEA Model and Perform Level 3 Fitness-for-Service Assessment of Critical Assets in Refinery & Process Industries. It also, talks about an engineer friendly plugin that helps in the data import with insights from the asset owners and FEA consultants.
IMU (inertial measurement unit) has already played significant roles in the control system of aerospace and other vehicle platforms. Due to the maturity and low cost of MEMS technology, IMU starts to penetrate consumer products such as smartphone, wearables and VR/AR devices.
This sharing will focus on the general introduction of IMU components, signal characteristics and application concepts, with an attempt to guide those who is interested in the IMU-based system integration and algorithm development.
Boundary Conditions for Seismic Imaging: Computational and Geophysical Point...EssamAlgizawy
Reverse Time Migration (RTM) is a powerful seismic imaging approach, widely used for migrating areas of complex structures of steep-dips and subsalt regions, despite its high computational cost. Advancing wave-field in time represents the main cost of the RTM as it is usually done by using Finite Difference (FD) to solve the wave-equation. Accuracy of the solution is subject to the approximation of the FD in both time and space.
Theoretically, waves propagate their extends to infinity or continue until vanishing. Unfortunately, this is not applicable in modelling a particular region since we truncate model to a computational grid modelling a region of interest. Absorbing all incoming energy at the boundaries of the computational grid mimics a real-life infinite media. Many approaches attempt to mimic different kinds of absorbing boundary conditions (ABC) e.g. Sponge, PML, random boundaries, etc. The objective of this study is to find the best compromise between geophysical and computational standpoint, and find the best quality of the attenuation with a minimum number of additional grid points.
We review 2 RTM implementations; the first one is using the standard approach (2 propagation with in-memory snapshots of the full wave-field with IPP compression) covering Sponge and CPML boundary conditions, while the second implementation uses random velocity boundaries that almost avoids IO but involves an extra propagation. Thereof we can balance the number of grid points in the damping area to find the best combination with respect to the computational efficiency of the RTM kernels.
This document discusses engineering change orders (ECOs) used to fix timing, functional, power, and clock issues after physical design and sign-off. It describes the motivation for ECOs due to tool limitations and differences between implementation and sign-off. Common ECO techniques are listed for timing (driver upsizing, buffer insertion, etc.), power (vt-swapping, downsizing, etc.), and metal-only ECOs. Timing ECO tools from Synopsys, Cadence, and other vendors are also mentioned. Upcoming ECO technologies like dynamic power optimization and automatic legalization are noted.
This document presents a method for assigning tasks to cores in a heterogeneous multi-core system on chip (MCSOC) to minimize energy consumption. It uses a simulated annealing algorithm to iteratively search for mappings that reduce energy usage. The algorithm was tested on an MCSOC model with ARM Cortex-A7 and A15 cores using benchmark tasks run in Gem5 simulations. Results show the algorithm can reduce energy consumption by up to 70% compared to a non-optimized mapping approach, with greater reductions seen at higher numbers of iterations. Runtimes for the algorithm range from under a second to over 4 minutes depending on the problem size and number of iterations.
This document discusses limitations of traditional serial scan design for testing integrated circuits and proposes an alternative called Random Access Scan (RAS). RAS addresses three key limitations of serial scan: 1) test data volume, 2) test application time, and 3) test power. In RAS, flip-flops act as addressable memory elements during test mode, reducing time to set and observe flip-flop states compared to serial scan. While RAS requires more gates and test pins than serial scan, it significantly reduces switching activity and power consumption during testing.
Binary alloy nanopatterning using low energy ion beams
Presentation_For_A_SPRA
1. www.inl.gov
Seismic Group Lead
Nuclear Science and Technology
Idaho National Laboratory
Justin Coleman, P.E.
May 20th, 2015
Advanced Seismic Probabilistic Risk
Assessment using Nonlinear Soil-Structure
Interaction Analysis
STIMS: INL/CON-15-35086
2. What is the Need for Nonlinear SSI?
KK 2007 Fukushima 2011 North Anna 2011
Design Value (g) 0.20 0.26 (Original)
0.45 (Update)
0.18
Recorded Value (g) 0.32 0.56 0.26
2
All Exceeded Design Ground Motion
• The estimated design ground motion has recently been exceeded at Nuclear Power Plants
• NLSSI needed to capture nonlinear behavior during larger earthquakes
• Gapping and Sliding
• Material Nonlinearity
3. Linear versus Nonlinear Analysis
• Larger magnitude seismic events
dominate risk calculations
• Linear elastic seismic analysis tools
are poor at predicting structural
performance during larger
earthquakes
• Nonlinear tools are needed to
evaluate risk in large magnitude
earthquake events, including beyond
design basis shaking
Linear Seismic
Analysis
Generally provides
conservative facility
design for low
amplitude events
Cannot model time-
based phenomena
which correlates
failures
Soil and structure
do not separate
Cannot quantify
margin to failure
Non-Linear
Seismic
Analysis
Better reflects
physics of NPPs
during larger
earthquakes, other
severe accidents
Can model time-
based phenomena
which correlates
failures
Soil and structure
can separate
Can quantify
margin to failure
3
5. 5
Project Specific Goals
• Goal: Develop advanced methods and tools that reduce
uncertainties and provide a best estimate understanding of seismic
risk
• Use advanced tools to investigate if in-structure response scales linearly
with ground motion
• Compare System Seismic Core Damage Frequency (SCDF) using
Traditional and Advanced SPRA
• Significant difference is Advanced SPRA credits gapping and sliding
• Determine if inclusion of gapping and sliding in NLSSI analysis changes
SCDF
• Develop method for using NLSSI (gapping and sliding) in SPRA
calculations
• NLSSI run times should be reasonable
• Need to limit number of NLSSI runs as much as possible
6. Brief Summary of Scope
• Perform Prob. Response Analysis of NPP Structure
– Linear SSI (CLASSI, frequency domain)
– Nonlinear SSI (LS-DYNA, time domain)
• Linear SSI Results Processing
– Develop fragilities per EPRI TR-103959
– SCDF for a plant system (Emergency Cooling Pump)
• Nonlinear SSI Results Processing
– Develop responses at multiple ground motion scale factors (3?)
– Response distribution at each ground motion level
– Capacity distributions independent of ground motion level
– Conditional failure probabilities by convolution per GM level
System conditional failure probability by Boolean math
– SCDF: convolve system conditional failure probability with hazard
7. NPP Structure & Plant System Components
Mode Freq.(Hz) Description
1, 2 5.27 1st horizontal mode for containment
3, 4 8.46 1st horizontal mode for internals
5, 6 12.37 2nd horizontal mode for internals
7 15.64 1st vertical mode for containment
8, 9 16.24 2nd horizontal mode for containment
10 27.83 1st vertical mode for internals
13, 14 32.89 3rd horizontal mode for internals
• Pump M-11
• Dist. Panel E-23
• Block Wall 2B-G2-1
• Battery E-58
• Medium V. Switchgear E-1
Structure Frequencies
System Components
8. Soil Properties
• Linear
– Elastic half space
– Basalt properties
– Representative median and β values assigned
• Nonlinear
– Nonlinearity limited to uplift and sliding
– Friction coefficient μ, median = 0.70, β = 0.25
Property Median Lognormal Std. Deviation
Unit Weight 159 lb/ft3 -
Poisson’s Ratio 0.35 -
Shear Wave Velocity 3,720 ft/sec 0.27
Shear Modulus 68,320 k/ft2 0.55
Damping 2% 0.4
9. Hazard and Ground Motion
• Hazard
– Reference Mean 1.0E-04 PGA is equal to 0.4g
– Objective is for NLSSI response to stay “linear” at Reference PGA
• GM
– Matched to horizontal and vertical UHS.
10. Linear SSI Fragility Results
Component Floor Am βc HCLPF
Pump 670-M-11 EL 61’ 2.70g 0.45 0.95g
Battery 670-E-59 EL 22’ 1.14g 0.28 0.59g
Dist. Panel 670-E-23
EL 61’ 1.60g 0.59 0.40g
Block Wall 2B-G2-1
EL 61’ 0.60g 0.28 0.31g
Switchgear 670-E-1
EL 22’ 1.90g 0.47 0.64g
11. Linear SSI SCDF Results
• With wall 3.5E-05
• No Wall 4.6E-06
12. 12
NLSSI Approach
• Commercial finite-element code (LS-DYNA)
• Several nonlinear hysteretic material models for soil, concrete, steel
• Explicit code
• No iterations, therefore faster in impact and contact problems
• Always stable below a maximum time step
• Maximum time step controlled by the stiffest and shortest element
• Mainly used in non-structural/geotechnical engineering applications
13. 13
NLSSI analysis: Procedure
665 ft 665 ft
214 ft
• Linear soil
• Rigid basemat
• Rayleigh damping for soil and
structure
• Element size ≈ 8 ft
(corresponds to max freq of
40Hz)
• Tried 2 domain sizes
• Verified by comparing surface
response at the edge of the
domain to free-field response
from a 1D SRA
14. 14
NLSSI analysis: Procedure
Outcrop input
CTOT = r×V × A
For a uniform soil halfspace,
outcrop input acceleration at any depth = free-field acceleration at the surface
• Boundary nodes at each
elevation are constrained to
move together
• No transmitting boundaries
used
16. 16
NLSSI analysis
• Run times (with 4 cores) for acceleration suite 1 (45 sec)
• 12 hours
• Analysis cases for LM:
• Basemat tied to the soil (no sliding or gapping)
• Separation allowed (sliding and gapping possible) and a coefficient of
friction of 0.8 is used
• Separation allowed (sliding and gapping possible) and a coefficient of
friction of 0.5 is used
18. 18
Conclusions
• Linear and NLSSI responses match well in the free field and on the
basemat for 0.4g
• Some differences are unavoidable
• No significant sliding is noticed for 0.4 g ground motion and coefficient of
friction at 0.8
• Sliding expected for larger ground motions
• Current problem is more complex than imagined for time-domain analysis
• Long computation time in time domain due to stiff beam elements
• Difference in beam formulations
• Idealization of the superstructure
• Traditional approach: as few elements as possible (suitable for frequency-
domain approach)
• Time-domain approach: larger time step; avoid, stiff, short elements
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Conclusions
• When applying appropriate methodologies NLSSI can be used to capture
realistic structural response (gapping and sliding) during larger ground
motions
• Next project steps
• Run 90+ sets of time histories for the NLSSI analysis
• Quantify in-structure response of these runs at locations of interest
• Calculate SCDF of NLSSI and compare with Linear SSI
July 16, 2007, Niigataken Chuetsu-Oki (Kashiwazaki-Kariwa) Earthquake
Original design seismic input was underestimated
Unit 4 base mat, recorded value NS 310 cm/s2 (0.32 g), design value NS 193 cm/s2 (0.20 g)
March 11, 2011, Great Tohoku Earthquake (Fukushima) and Tsunami
Earthquake damaged equipment necessary for ensuring safety
Seismic guidelines for nuclear plant construction set “remarkably low”
August 23, 2011, North Anna Earthquake
First instance of an operating reactor in US exceeding its design limit for ground acceleration
Sketch of an LS-DYNA model (isometric view) explaining
Soil domain dimensions
Soil model (linear)
Damping value (type of damping later)
Elevation view explaining:
Boundaries (lateral and base)
Ground motion input and basis for the type of input
Verification: free-field vs outcrop
Contact