Energy absorption capacity is one of the most important criterion in selecting materials for many engineering applications, such as crushing elements in cars, bicycle helmets, hard hats use construction sites and protective packaging of fragile goods. the materials or devices used as impact energy absorbers should utilize the plastic deformation as major energy-absorbing mechanism, In addition a light weight would be an attractive attribute in their applications. Particularly attractive of 3D dimensional textile performs are improved damage tolerance and the benefit of near net shape(cellular) manufacturing. The most attention has been given to 3D composites manufactured by the textile techniques of weaving, braiding, stitching and knitting. In this project two kind of knitted structures, simple single jersey (plain) and double jersey (rib) with two density( high and low) of textured multi-filament nylon 150 deneir were knitted. The fabric was placed on the plate include geometric dimensions, truncated cone and hemisphere with both low and high density, Another drilled page was placed on fabric in such a manner that the fabric was clamped between two plates by bolts in around of plates. Then this set was placed in oven with temperature 180? C and duration of 5 minutes and thermoforming action was ran. Three-dimensional fabric was covered by the epoxy resin. Then, to achieve an ideal energy absorbing, resin covered three-dimensional fabric was placed in a polymer substrate. PVC foam is suitable for this, was selected. The foam energy absorber to achieve an ideal state should have elastic and thus the foaming agent was applied. The exact amount of PVC and foaming agent plus precise determination processing factors such as temperature and curing time was achieved.The specimen was prepared by standard mould that the three-dimensional fabric was placed in between of the mould, Then the PVC foam with the same amount was poured in to the mould on both sides of the fabric. Then the mould was placed in the oven with specific heat and time. Specimens based on the Taguchi L8 design test method was prepared and the quasi-static tensile and pressure and dynamic impact (Drop weight) tests were ran. Results of the mini tab software was analyzed and optimized sample among the samples, the sample reinforced by the structure of high density rib with high density truncated con showed the highest strength in the tensile and pressure testes, samples with the same mentioned conditions, but in the form of hemisphere, has highest energy absorption in impact test. Then with the aid of the software, the optimal sample with PVC foam (specimen without reinforcement) was compared, and the results indicate that using 3D knitted fabric reinforcement in PVC foam is significant.
