Development of a finite element modelling for short fiber reinforced rubber composites using insert elements

Short fiber reinforced rubber composites (SFRRCs) are crucial, lightweight, and durable materials used across various industries. We've developed a simulator for full rubber belt-pulley friction contact behavior utilizing the large-scale parallel FE structural software FrontISTR. However, accurately integrating SFRRC's complex material behavior into this already large-scale simulation presented a significant challenge: traditional solid element modeling for both rubber and fibers proved impractically expensive. To overcome this, we developed and added an insert element function to FrontISTR. This function represents short fibers as embedded truss elements within the solid rubber matrix and supports distributed-parallel computation based on domain decomposition. The proposed method was verified by comparing the results obtained using the specimen model with actual short fiber orientations to those from commercial software. Our approach significantly reduces the computation time, achieving a speed-up of 400 times compared to conventional analysis with solid elements.