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The purpose of this paper is to optimize a new thin-walled cellular configurations with crashworthiness criteria, so as to improve the crashworthiness of components of a vehicle body.

ANSYS Parametric Design Language is used to create the parameterized models so that the design variables can be changed conveniently. Moreover, the surrogate technique, namely response surface method, is adopted for fitting objective and constraint functions. The factorial design and D-optimal criterion are employed to screen active parameters for constructing the response functions of the specific energy absorption and the peak crushing force. Finally, sequential quadratic programming-NLPQL is utilized to solve the design optimization problem of the new cellular configurations filled with multi-cell circular tubes under the axial crushing loading.

Two kinds of distribution modes of the cellular configurations are first investigated, which are in an orthogonal way and in a diamond fashion. After comparing the optimized configurations of the rectangular distribution with the annular distribution of the multi-cell fillers, it is found that the orthogonal way seems better in the aspects of crashworthiness than the diamond fashion.

The two new thin-walled cellular configuration are studied and optimized with the crashworthiness criteria. Study on the new cellular configurations is very valuable for improving the crashworthiness of components of a vehicle body. Meanwhile, the factorial design and the factor screening are adopted in the process of the crashworthiness optimization of the new thin-walled cellular configurations.

Among various efforts pursued to produce fuel efficient vehicles, light weight engineering (i.e. the use of low‐density structurally‐efficient materials, the application of advanced manufacturing and joining technologies and the design of highly‐integrated, multi‐functional components/sub‐assemblies) plays a prominent role. In the present work, a multi‐disciplinary design optimization methodology has been presented and subsequently applied to the development of a light composite vehicle door (more specifically, to an inner door panel). The door design has been optimized with respect to its weight while meeting the requirements /constraints pertaining to the structural and NVH performances, crashworthiness, durability and manufacturability. In the optimization procedure, the number and orientation of the composite plies, the local laminate thickness and the shape of different door panel segments (each characterized by a given composite‐lay‐up architecture and uniform ply thicknesses) are used as design variables. The methodology developed in the present work is subsequently used to carry out weight optimization of the front door on Ford Taurus, model year 2001. The emphasis in the present work is placed on highlighting the scientific and engineering issues accompanying multidisciplinary design optimization and less on the outcome of the optimization analysis and the computational resources/architecture needed to support such activity.

The purpose of this paper is to develop a new multi-objective optimization procedure for crashworthiness optimization of thin-walled structures especially circular tubes with functionally graded thickness.

The proposed optimization approach is based on finite element analyses for construction of sample design space and verification; gene-expression programming (GEP) for generating algebraic equations (meta-models) to compute objective functions values (peak crash force and specific energy absorption) for design parameters; multi-objective genetic algorithms for generating design parameters alternatives and determining optimal combination of them. The authors have also utilized linear and non-linear least square regression meta-models as a benchmark for GEP.

It is shown that the proposed approach is able to generate Pareto optimal designs which are in a very good agreement with the actual results.

The paper presents the application of a genetic programming-based method, namely, GEP first time in the literature. The proposed approach can be used to all kinds of related crashworthiness problems.

The purpose of this paper is to improve the crashworthiness of aircraft by using the strut system as an energy absorption device without redesigning other components.

The novel strut system consists of metal stepped thin-walled tubes and articulated connecting hinges. The strut is suffering axial load during impact process for rotating of hinges, and the metal stepped tube has an inversion failure behaviour.

The metal stepped tube has lower initial impact load and more stable failure behaviour. The geometrical factors have a great influence on the impact load and energy absorption efficiency. The best length ratio between upper and lower sections is about 2:1 and 1:1 for the metal stepped circular and square tubes, respectively.

The metal stepped tube with inversion mechanism is suitable for aircraft strut system to improve crashworthiness performance.

A new strut system is provided using metal inversion failure stepped tubes and articulated connecting hinges to improve crash worthiness of aircraft.

This chapter provides a taxonomy of key rolling stock types and covers the key engineering principles. This chapter concentrates on the aspects of the rolling stock that make it sustainable in terms of passenger transportation; these aspects are primarily safety and crashworthiness. These are specific items that contribute to make the rolling stock and hence rail system more sustainable; passengers need to be confident that they are travelling in safe rolling stock and the vehicle consist, manufacturing technique or materials used should not compromise the crashworthiness aspects. For this reason, all aspects of this chapter reference vehicle safety and crashworthiness.

The purpose of this paper is to provide a methodology with which to perform variable screening and optimization in automotive crashworthiness design.

The screening method is based on response surface methodology in which linear response surfaces are used to create approximations to the design response. The response surfaces are used to estimate the sensitivities of the responses with respect to the design variables while the variance is used to estimate the confidence interval of the regression coefficients. The sampling is based on the D‐optimality criterion with over‐sampling to improve noise filtering and find the best estimate of the regression coefficients. The coefficients and their confidence intervals as determined using analysis of variance (ANOVA), are used to construct bar charts for the purpose of selecting the important variables.

A known analytical function is first used to illustrate the effectiveness of screening. Using the finite element method (FEM), a complex vehicle occupant impact problem and a full vehicle multidisciplinary problem featuring frontal impact and torsional modal analysis of the vehicle body are modeled and parameterized. Two optimizations are conducted for each FEM example, one with the full variable set and one with a screened subset. An iterative, successive linear approximation method is used to achieve convergence. It is shown that, although significantly different final designs may be obtained, an appropriately selected subset of variables is effective while significantly reducing computational cost.

The method illustrated provides a practical approach to the screening of variables in simulation‐based design optimization, especially in automotive crashworthiness applications with costly simulations. It is shown that the reduction of variables used in the optimization process significantly reduces the total cost of the optimization.

Although variable screening has been used in other disciplines, the use of response surfaces to determine the variable screening information is novel in the crashworthiness field.

These are the proceedings of a symposium held at Stamford University and include a complete section on aircraft crashworthiness with a survey of rotary wing aircraft crashworthiness by G. T. Singley. In this he reviews and analyses the findings of the 11 year crash survival research and development programme conducted by the Eustis Directorate and covers accident investigation, crash testing of full‐scale, fully instrumented aircraft, crash injury and crashworthiness evaluation of aircraft, and aircraft mockups; and selected component and subassembly testing. An assessment of energy absorbing devices for prospective use in aircraft impact situations is made by A. A. Ezra and R. J. Fay. The subject is defined as the specific energy absorption capacity per unit weight of device or system, the efficiency of the stroke, the stroke to length ratio, the reliability, the repeatability, the ability to sustain rebound loads and the cost. Human tolerance limitations related to aircraft crashworthiness by A. I. King outlines the problems encountered in the scaling of animal data to the human level and in the correlation of single‐directional tolerance data to actual multi‐directional impacts. Jack Collins and James W. Turnbow consider the response of a scat passenger system to impulsive loading in which they present maximum system forces, displacements, velocities and accelerations as functions of velocity change, aircraft deceleration, crash pulse shape, passenger weight and scat belt slack. Also of especial interest is “Flutter prevention in design of SST” by M. J. Turner and J. B. Bartley which they discuss in relation to configuration constraints resulting from mission performance requirements. This is included in a section on structural systems and other sections in the book concern structural elements, materials and solids.

The paper focuses on two topics, optimizing the proposed triangular tube for crashworthiness and solving a non‐linear programming problem by a “mapping” technique, which the condition of Lagrange Multiplier Theorem is violated within the feasible region. The purpose of studying optimized triangular tubes is to prepare them for redesigning vehicle bumpers. The dimension optimization of triangular tube is carried out for its thickness and lateral length, based on the accomplished shape optimization under an impact. The load uniformity is taken as the objective function, which is defined as the ratio of maximum peak force and means crushing force. Meanwhile the mean crushing force and absorbed energy are treated as constraints. Based on FEA analysis, the regression functions for load uniformity, mean crushing force, and absorbed energy are formulated by RSM. The result has shown that triangular tube possesses an optimization region, under which the better‐integrated property can be achieved to supply a more safety environment for vehicular occupants.