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Traditional composite materials constituted by long fiber oriented along one direction presents optimum stiffness and strength material properties, when the stress main direction is parallel to the fiber. However, these conventional constructions of composite laminates present poor out of plane mechanical properties and require several manufacturing steps, resulting in high production costs. A solution to these problems come from the application of tridimensional textile technologies to composite preforms manufacturing. This technology includes braiding, 3D weaving, weft knitting, multilayer sewing 4/5D and stitching as preforms joining technique. These technologies allow the production of near-net complex fiber preforms, achieving significant reductions of labor and manufacturing costs.

In this paper, the prototypes of electric cars done by the Engineering & Infrastructure Transportation Area in the Department of Mechanical Engineering of the University of Zaragoza is presented. The project started in 1993, the initial stage started doing calculation and construction of prototype I which was used as a technological demonstrator. The prototype I, was a very simplified electric vehicle with particular performance qualities. Prototype II has the features of an urban car comparable to the current combustion cars for urban purposes. A program of testing will be done in order to find problems that can be corrected for the prototype III, in which all the parameters analyzed will be corrected for a serial manufacture.

A car front energy absorber made of composite materials is analyzed in this work. Mechanical requirements (static and crash behavior), geometry, load and boundary conditions are described in the first part of this study. A finite element simulation has been performed in order to obtain the mechanical behavior of the absorber. The experimental analysis was also carried out: displacements, strains and stresses were obtained by means of mechanical testing of the absorber. An outstanding correlation between the theoretical and experimental results will be shown. Finally, a comparison between metallic and non-metallic car front energy absorbers will be presented in the chapter of conclusions.