Topology optimization of metal and fiber reinforced plastic (FRP) structures under loading uncertainties 2019-01-0709
Fiber reinforced plastic (FRP) composite materials have gained particular interests attributable to their high specific modulus, high strength, lightweight and perfect corrosion resistance. However, in reality, FRP composite materials cannot be used alone in some critical places such as positions of joints with hinges, locks. Therefore, metal reinforcements are usually needed in local positions to prevent structure damage. Besides, if the uncertainties present, the obtained optimal structures may experience in failures as the optimization usually pushes the solution to the boundaries of constraints and has no room for tolerance and uncertainties, so robust optimization should be considered to accommodate the uncertainties in real word.
This paper proposes a mixed topology method to optimize metal and fiber reinforced plastic composite materials simultaneously under nondeterministic load with random magnitude and direction. A joint cost function, subject to the constraints of local displacements and primary natural frequency, is employed to contain both the mean and standard deviations of compliance in the robust optimization. The sensitivities of the cost function and constrains are derived with respect to the design variables in a nondeterministic context. The discrete material optimization (DMO) technique is used here to undertake robust topology optimization for FRP composites and metal material. In this study, two examples are presented to demonstrate the effectiveness of the proposed methods. The robust topology optimization results exhibit that the composite structures with proper distributions of materials and orientations are of more stable performance when the load fluctuates.
Yunkai Gao, Yanan Xu, Chi Wu, Jianguang Fang
Tongji Univ, Tongji Univ., The University of Sydney, University of Technology Sydney,