Design of Light Weight Footstep Using Continuous Glass Fiber Reinforced Plastic Brackets 2019-28-0172
Utility or Off-road vehicles are characterized with their higher ground clearances. Higher ground clearance of vehicle requires the vehicle to have footsteps for easy entry and exit of passengers from the vehicle. A typical foot step construction consists of structural steel brackets with an Aluminium or plastic top panel. Conventional steel construction is heavier to meet weight bearing capacity and durability requirements. Our objective of this work is to explore lightweight materials which can meet these performance requirements with a lighter construction. We chose to study the continuous glass fiber reinforced plastic as an alternative to the metal construction.
The continuous glass fibers in the PP matrix improves the material strength due to high strength to weight ratio. The strength of the matrix increases depending on the fiber length in the matrix. This technology uses twin screw extrusion and plunger type injection to retain the fiber length in the molded part which helps the part to bear higher loads depending upon the aspect ratio of fibers in the matrix. We have produced test samples of glass reinforced PP matrix for material properties evaluation and the results are discussed and compared in this paper.
Further , we discuss in detail the concept design of the glass fiber reinforced plastic brackets which acts as load bearing structure. We have used Opti struct nonlinear static solver for analyzing the strength of foot step and its feasibility. Meshing is done with shell elements using Hyper mesh. Spots are modeled using ACM2 weld. Bolts and rivet connections are modeled using rigid element RBE2. Contact between the parts are modeled using slide option available in Opti struct. We discuss the CAE results and various geometry optimizations carried out to achieve performance similar to the conventional metal bracket footstep.
The Continuous glass fiber reinforced plastic structural brackets using injection molding compounding process offers excellent potential to reduce the weight of the structural parts which are otherwise made of steel. The weight savings of nearly 40 percent has been achieved in this case study when compared to conventional steel frame footstep. This process can also make parts with complicated shapes, better dimensional control and aesthetic appeal.
Praveen Kumar, Vivek KV Shenoy, Ashish Kumar Sahu, Srivatsa Sriperumbudur, Anton Kumanan, K V Balaji
Mahindra & Mahindra, Ltd.
International Conference on Advances in Design, Materials, Manufacturing and Surface Engineering for Mobility