摘要:

This study evaluates the biofidelity and response characteristics of the Thor Lx dummy lower extremity prototype. Static and dynamic tests were performed to evaluate its response relative to that of cadavers and the Hybrid III (45° dorsitlexion ankle and soft joint stop). Static tests determined the ankle joint moment properties, ankle/tibia axial stiffness, and the mass and moments of inertia. The three different limbs were subjected to two different types of dynamic tests: pure dorsiflexion and a combination of dorsiflexion and axial load. The results show that the response characteristics of the Thor Lx better reflect those of the cadaver limbs, which indicates that the Thor Lx design is an improvement over the Hybrid III. The continuous ankle joint stiffness eliminates joint property discontinuities at the extreme ranges of motion, and the non-concentric joint locations of the Thor Lx mimic the ankle and sub-talar joints in the human. The Achilles tendon of the Thor Lx serves as passive musculature and increases ankle stiffness in dorsitlexion. A compliant element in the tibia shaft gives more biotidelic tibia axial load characteristics, and the straight shaf eliminates artificial moments created by axial loading. With its design modifications and comprehensive instrumentation package, the Thor Lx is capable of providing a more complete and biofidelic assessment of lower limb response and injury risk.

ISSN:1358-8265    

DOI:10.1533/cras.2000.0129

出版商:Woodhead Publishing Ltd    

年代:2000

数据来源: Taylor

摘要:

Bullnose guardrail systems are used to protect vehicles from hazards in the median of divided highways. The Midwest Roadside Safety Facility is currently designing and testing a new bullnose system that will meet relatively new Federal safety performance specifications. After developing a system that successfully handled frontal impacts, attention was then focused on impacts along the side required of such systems. What is considered the most demanding design test condition along the side, known as the critical impact point, proved difficult. After a failed crash test, using non-linear finite element analysis, the system was analysed, modifications put forth and studied, and a recommended new design was proposed. Subsequently, the proposed design was successfully crash tested at 100 km/h at the critical impact point.

ISSN:1358-8265    

DOI:10.1533/cras.2000.0130

出版商:Woodhead Publishing Ltd    

年代:2000

数据来源: Taylor

摘要:

The subject of this investigation is the development of an accurate simulation of a truck impacting a commonly found strong post/w-beam guardrail system. Detailed methods for system simulation are proposed herein and several major issues, namely. the use of springs to simulate component crashworthiness behaviour, are investigated. Rail to block-out bolt connection, soil-post-dynamic interaction, and effect of ends of guardrail are modelled and simulated. Soil-post interaction is modelled using both Lagrangian and Eulerian meshes and the results using the two methods are presented herein. Both qualitative and quantitative validation of the crash simulation is presented and discussed. The present paper provides a roadmap for the simulation of highway safety structures.

ISSN:1358-8265    

DOI:10.1533/cras.2000.0131

出版商:Woodhead Publishing Ltd    

年代:2000

数据来源: Taylor

摘要:

This paper presents an innovative device for use as an impact energy absorber. The absorber consists of a central solid core surrounded by a cell containing circular solid rods. The entire assembly is enclosed inside a circular cylinder. Radial forces between the core and the rods surrounding it are controlled by means of setscrews and nuts fixed on the cylinder. Energy is dissipated by friction forces generated at the contact surfaces when the central core is displaced axially in either direction. Smartness of this absorber is achieved by making the rate of the absorber variable depending on the input kinetic energy of the vehicle.

ISSN:1358-8265    

DOI:10.1533/cras.2000.0132

出版商:Woodhead Publishing Ltd    

年代:2000

数据来源: Taylor

摘要:

Classical and non-classical implicit time integration schemes are presented for the transient response of highly nonlinear problems of large deformation analysis exhibiting important material energy dissipation. Surprisingly these schemes lead to excellent convergence properties that make them cost efficient alternative to explicit schemes generally advocated as the best choice for these problems. Numerical illustrations presented herein show the crushing of a shock-absorber device, as well as the resolution of the dynamical buckling of a thin-walled steel cylinder. In these examples, it is shown that implicit schemes are more efficient and require less CPU-cost for a given precision of the contact situation and higher precision reachable than the explicit scheme. Both of which are using the Penalty method for the treatment of the contact problem.

ISSN:1358-8265    

DOI:10.1533/cras.2000.0133

出版商:Woodhead Publishing Ltd    

年代:2000

数据来源: Taylor

摘要:

The present paper describes the implementation of the “implicit” finite element code MARC in the simulation of the crush behaviour of cylindrical thin-walled composite tubes under bending. The specimen is loaded as a cantilever beam in a self-made experimental set-up under various holding conditions. The predicted numerical results are compared with those obtained in actual experimental tests. The comparisons are made in terms of deformation modes, i.e. load/deflection history and crush zone characteristics, and of energy absorbing capacity/crashworthiness characteristics, which show quite good agreement. The problem is treated by the FE code with a reasonable amount of computer time, allowing, in this manner, such structural components to be designed and analyzed without having to build and test expensive prototypes.

ISSN:1358-8265    

DOI:10.1533/cras.2000.0134

出版商:Woodhead Publishing Ltd    

年代:2000

数据来源: Taylor

摘要:

The use of recycled paper-rolled tubes as potential impact energy absorbing elements has been experimentally explored. Single and bundled (cellular) tubes have been subjected to quasi-static axial and lateral crushing loads. Effect ofL/D,D/tratios and loading rate on the energy absorbing performance of such tubes have been considered. The load-deflection curves of the axially and laterally crushed paper tubes exhibit some of the favourable characteristics of energy absorbing elements which includes low load uniformity ratio, long stroke and reasonable specific energy. The paper-rolled tubes, in single or cellular form, are light, economical, made of recyclable and pollution-free material and above all have a reasonable specific absorption energy which makes them a favourable candidate for energy absorption.

ISSN:1358-8265    

DOI:10.1533/cras.2000.0135

出版商:Woodhead Publishing Ltd    

年代:2000

数据来源: Taylor

ISSN:1358-8265    

DOI:10.1533/cras.2000.0218

出版商:Woodhead Publishing Ltd    

年代:2000

数据来源: Taylor