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Researchers at the Center have experience in the design, analysis, testing, and evaluation of roadside safety hardware including:
- bridge rails,
- median barriers,
- guardrail-to-bridge rail transitions,
- guardrail end treatments,
- crash cushions,
- breakaway support structures, and
- portable concrete barrier systems.
Researchers design these devices to satisfy the impact performance requirements of the Manual for Assessing Safety Hardware (MASH), which is published by the American Association of State Highway Transportation Officials (AASHTO). This document contains recommended procedures for the safety performance evaluation of highway features. Any new roadside safety devices must comply with MASH before being accepted by the Federal Highway Administration (FHWA) for use on the National Highway System (NHS).
Crash tests are often conducted in support of the development and evaluation of these safety devices. Such tests are conducted at the TTI Proving Ground located at Texas A&M University’s Riverside Campus. The TTI Proving Ground is an International Standards Organization (ISO) 17025 accredited laboratory with American Association for Laboratory Accreditation (A2LA) Mechanical Testing certificate 2821.01. The TTI Proving Ground is staffed by highly-skilled personnel who fabricate and construct test articles, conduct crash tests, and process, analyze, and report crash test data. These crash tests are used to verify design viability and impact performance before a system implementation.
Additionally, researchers at the Center actively work on the design, analysis, testing, and evaluation of perimeter security devices including:
- gates, and
These anti-terrorist devices are designed to arrest attaching vehicles and limit their penetration into a protected facility. Researchers design these devices to meet the impact performance requirements of ASTM F2656-07 “Standard Test Method for Vehicle Crash Testing of Perimeter Barriers.” This standard is intended to ensure that perimeter security devices provide a specified level of vehicle impact resistance. It provides a range of vehicle impact conditions, test designations, and penetration levels that allow agencies to select devices that satisfy their facilities needs.
Research within the Center also addresses the influence of roadside geometric features such as driveways, slopes, ditches, shoulders, and medians on the safety of vehicles encroaching into the roadside environment. Researchers use computer simulation codes to better understand the nature and severity of roadside encroachments, quantify vehicle dynamics, evaluate safety countermeasures, and develop design guidelines.
Nonlinear finite element analysis advantage extends to the area of infrastructure protection. Experimentation at such large scale is cost prohibited if not impossible. The researchers have been involved in several efforts to identify impact force or quantify the performance of a protection concept. The simulation team at TTI is intimately engaged in dynamic performance of infrastructures under impact including bridges, bridge piers, MSE walls and others.
Bridge Pier Impact by Heavy Trucks
The interaction between a heavy truck and a bridge pier can be modeled using finite element methodology. Many aspects of this interaction can be modeled and simulated in details. The designer/analyst can study the impact force imparted into the pier given a type of ballast (rigid or soft).
Detailed model of the pier frame structure is useful in defining the dynamic stiffness of the frame for further analyses of the dynamic response of the pier.
Advances in computational algorithms and computer hardware allow researchers to perform detailed investigation of engineering systems using high fidelity computational models. Another benefit of these advances is the capability to perform multiple iterations of such simulations to identify a better or an optimum design of a given engineering system. Optimization technology in engineering applications consists of two large themes, topology optimization and size optimization. Topology optimization methods work on finding the optimum distribution of material for a given system. On the other hand, Size optimization methods work on finding the optimum parameters (thicknesses…etc.) for a given system. However, other capabilities including sensitivity analysis, parameter identification, morphing, probabilistic and reliability analysis, sampling and design of experiments became integral of many optimization codes. The figures beneath depict the results of topology optimization of a cantilevered I-beam steel subjected to edge loading.
Two optimization analyses were conducted, one allowing redistributing the material of the web only while the other was for allowing redistributing both the web and the flanges materials. In the first case the optimization resulted in 23% reduction in the mass of the beam while in the second case the optimization resulted in 55% reduction in the mass of the beam.
The ability to constrain what can be changed and impose certain limits on the design during the optimization process allows the researchers to come with a design that is both optimum and physically attainable to build.
Reverse Engineering/Vehicle Modeling Technology
Recently, the Center has acquired a laser scanning hardware. This FARO laser scanning arm is capable of scanning the surface of objects to relay back a three-dimensional model of the object via specialty software RapidForm. This technology allows the researchers to reverse engineer test vehicles and other components related used in crash testing. This technology helps the researchers in providing enhanced finite element representation of existing and/or new test vehicle specification.