Download or read book Finite Element Modeling of Cable Median Barriers Used in Crash Simulations written by Amol Arun Gaikwad and published by . This book was released on 2008 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, a new finite element (FE) model of cable median barriers (CMBs) is developed and compared with an existing CMB model developed at the National Crash Analysis Center (NCAC). Crash simulations involving roadside safety structures such as CMBs, are challenging due to the nonlinear mechanism of crashes, large sizes of simulation models, and the large amount of contact analyses. Existing CMB models, particularly the NCAC model, create considerable computational challenges in terms of efficiency and stability when used in full-scale crash simulations. To this end, developing a computationally efficient and numerically stable CMB model will significantly enhance the modeling capability in this area of research. In this study, we investigate some of the issues of the NCAC CMB model and develop a new CMB model with improved computational efficiency and numerical stability. The new CMB model is compared to the NCAC CMB model in full-scale FE simulations, evaluating the contact behavior of cables as well as other components. The computational cost of the new CMB model is also checked for improvement on the efficiency of the NCAC model.

Download or read book Modeling Cables and Impactors in Crash Analysis written by Michael Eric Martin and published by . This book was released on 2009 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cable median barriers (CMBs) have become a popular roadside safety device for preventing cross-median collisions. It is common to model barrier collisions using finite element analysis (FEA). One of the most important and difficult interactions to model is the interaction between the vehicle and the cables. Currently used cable models incorporate null shells as contact surfaces around beam elements that often cause snagging with the vehicle's components and can exhibit unrealistic contact behavior. Since LS-DYNA supports direct contact definitions with beam elements, it would be ideal to model cables with only beam elements to reduce the number of elements and thus the computational cost. An analytical program is presented to validate both the current cable model and the new one based only on beam contacts. Results from finite element (FE) static and dynamic simulations are presented and compared to closed-form solutions to verify the current and new cable models. A rigid bar-rigid impactor problem is presented to validate and compare the contact behavior when various contact definitions and contact interfaces are implemented. FE simulations of an impactor-cable system are also presented to examine contact interactions when one of the bodies is flexible. These impact simulation results are compared to closed-form analyses. Finally, full-scale FE CMB crash simulations are performed using both contact strategies. The results are compared and simulation durations for each model are also presented. It is shown that the use of null shells for contact purposes is not necessary, since they increase computational cost and are responsible for inaccuracies and instabilities in the models.

Download or read book Finite Element Evaluation of Two Retrofit Options to Enhance the Performance of Cable Median Barriers written by Hongbing Fang and published by . This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes the research efforts of using finite element modeling and simulations to evaluate the performance of W-beam guardrails and cable median barriers on six-lane, 46-foot median divided freeways. A literature review is included on performance evaluation of W-beam guardrails and cable barriers as well as applications of finite element modeling and simulations in roadside safety research.

Download or read book Finite Element Evaluation of Two Retrofit Options to Enhance the Performance of Cable Median Barriers written by Howie Fang and published by . This book was released on 2009 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes the research efforts of using finite element modeling and simulations to evaluate the performance of W-beam guardrails and cable median barriers on six-lane, 46-foot median divided freeways. A literature review is included on performance evaluation of W-beam guardrails and cable barriers as well as applications of finite element modeling and simulations in roadside safety research.

Download or read book Median Barrier Placement on Six Lane 46 Foot Median Divided Freeways written by Hongbing Fang and published by . This book was released on 2010 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Materials and Contact Characterisation IX written by S. Hernández and published by WIT Press. This book was released on 2019-07-23 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt: Including papers from the 9th edition of the International Conference on Computational Methods and Experiments in Material and Contact Characterisation this volume presents the work of selected researchers on the subject. Material and contact characterisation is a rapidly advancing field and this volume contains the latest research. Of particular interest to industry and society is the knowledge of surface treatment and contact mechanics of these materials to determine the in-service behaviour of components subject to contact conditions. Modern society requires systems that operate at conditions that use resources effectively. In terms of components durability, the understanding of surface engineering wear frictional and lubrication dynamics has never been so important. Current research is focussed on modification technologies that can increase the surface durability of materials. The characteristics of the system reveal which surface engineering methods should be chosen and as a consequence it is essential to study the combination of surface treatment and contact mechanics. The accurate characterisation of the physical and chemical properties of materials requires the application of both experimental techniques and computer simulation methods in order to gain a correct analysis. A very wide range of materials, starting with metals through polymers and semiconductors to composites, necessitates a whole spectrum of characteristic experimental techniques and research methods. The papers in the book cover a number of topics, including: Computer methods and simulation; Experimental and measurement techniques; Mechanical characterisation and testing; Materials under extreme conditions; Polymers and plastics; Advances in composites; Micro and macro characterisation; Corrosion and erosion; Damage, fatigue and fracture; Recycled materials; Materials and energy; Surface problems and contact mechanics; Surface modification and treatments; Thick and thin coatings; Tribomechanics and wear mechanics; Biomechanical characterisation; Biomechanical applications and Case studies.

Download or read book Encyclopedia of Transportation written by Mark Garrett and published by SAGE Publications. This book was released on 2014-08-13 with total page 2000 pages. Available in PDF, EPUB and Kindle. Book excerpt: Viewing transportation through the lens of current social, economic, and policy aspects, this four-volume reference work explores the topic of transportation across multiple disciplines within the social sciences and related areas, including geography, public policy, business, and economics. The book’s articles, all written by experts in the field, seek to answer such questions as: What has been the legacy, not just economically but politically and socially as well, of President Eisenhower’s modern interstate highway system in America? With that system and the infrastructure that supports it now in a state of decline and decay, what’s the best path for the future at a time of enormous fiscal constraints? Should California politicians plunge ahead with plans for a high-speed rail that every expert says—despite the allure—will go largely unused and will never pay back the massive investment while at this very moment potholes go unfilled all across the state? What path is best for emerging countries to keep pace with dramatic economic growth for their part? What are the social and financial costs of gridlock in our cities? Features: Approximately 675 signed articles authored by prominent scholars are arranged in A-to-Z fashion and conclude with Further Readings and cross references. A Chronology helps readers put individual events into historical context; a Reader’s Guide organizes entries by broad topical or thematic areas; a detailed index helps users quickly locate entries of most immediate interest; and a Resource Guide provides a list of journals, books, and associations and their websites. While articles were written to avoid jargon as much as possible, a Glossary provides quick definitions of technical terms. To ensure full, well-rounded coverage of the field, the General Editor with expertise in urban planning, public policy, and the environment worked alongside a Consulting Editor with a background in Civil Engineering. The index, Reader’s Guide, and cross references combine for thorough search-and-browse capabilities in the electronic edition. Available in both print and electronic formats, Encyclopedia of Transportation is an ideal reference for libraries and those who want to explore the issues that surround transportation in the United States and around the world.

Download or read book Department of Transportation and Related Agencies Appropriations for 2003 2003 budget justifications written by United States. Congress. House. Committee on Appropriations. Subcommittee on Department of Transportation and Related Agencies Appropriations and published by . This book was released on 2002 with total page 1830 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Surface Effects and Contact Mechanics XI written by J. Th. M. De Hosson and published by WIT Press. This book was released on 2013 with total page 337 pages. Available in PDF, EPUB and Kindle. Book excerpt: Containing the papers from the eleventh biennial conference on the topic, first held in 1993, this book covers contact mechanics and surface effects and their interaction, so important in modern engineering. The life and performance of structural components is affected by surface conditions such as wear, corrosion and, high cycle fatigue. Surface treatments that address contact conditions can reduce costs by extending the life of components. Hence the importance of the conference discussions.The book's papers cover such matters as Experimental and measurement tests; Fracture fatigue and mechanics; Surface modification; Surface problems in contact mechanics; Thick and thin coatings; Heat transfers; Multiscale experiments and modelling; Computer simulation; Biocompatible materials; Vacuum technologies; Residual stress problems; Tribomechanics; Case studies.

Download or read book Guidance for the Selection Use and Maintenance of Cable Barrier Systems written by and published by . This book was released on 2012 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report provides guidance for the selection, use, and maintenance of cable barrier systems. While cable barrier systems have been in use for more than 70 years, their use has been on the rise and is expected to continue in the future. The increase in use of cable barrier systems has been attributed to the success rate in keeping vehicles from crossing the median, reducing roadway departures, and decreasing impact severity. Due to advancements in cable barrier system technology, installation and repair costs are lower and cable barrier use has increased in varying roadway environments. Safety studies, although limited, have shown that cable barriers help reduce those median cross-over collisions that lead to some of the most severe head-on type crashes. This document will be of particular interest to design, maintenance, traffic, and safety engineering professionals.

Download or read book Basic Study to Improve Speed and Efficiency of Vehicle barrier Simulations Volume II Appendixes Final Report written by R. L. Chiapetta and published by . This book was released on 1990 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High Tension Cable Median Barrier Safety Effectiveness Evaluation written by Richard Storm and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this study was to evaluate the change in crash frequency or severity of varying lateral offset distances of high-tension cable median barriers in Minnesota. Crash and traffic data from 2016 to present were conjoined with roadway cross-sectional data and high-tension cable barrier locations to perform cross-sectional analyses for interstate segments equal to or greater than 0.05-miles long. Negative binomial regression models were estimated and used to develop crash modification factors (CMFs) for the following crash types: total crashes, target crashes, and barrier crashes. In addition to evaluating the impact of lateral offset, a naïve before-after evaluation was completed to quantify the impact of installing high-tension cable barrier.

Download or read book Finite Element Simulation of Indy Racetracks HDPE Crash Barriers Using LS DYNA written by Sridhar Ravikoti and published by . This book was released on 2001 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling the Interaction of Heavy Vehicles with Protective Barriers Volume I Development and Validation of the CRUNCH Program Final Report written by N. R. Iwankiw and published by . This book was released on 1980 with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluation of Cross Median Crashes written by Hampton Clay Gabler and published by . This book was released on 2005 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Department of Transportation and Related Agencies Appropriations for 2003 written by United States. Congress. House. Committee on Appropriations. Subcommittee on Dept. of Transportation and Related Agencies Appropriations and published by . This book was released on 2002 with total page 1836 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structures Under Shock and Impact XI written by Norman Jones and published by WIT Press. This book was released on 2010 with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text examines the interaction between blast pressure and surface or underground structures, whether the blast is from civilian, military, dust and natural explosions, or any other source.