Optimal configuration of magnetoelectric composites under various mechanical boundary conditions

The magnetoelectric (ME) coupling effect of magneto-electro-elastic composites is generated by the product property of magnetostriction and piezoelectricity via elastic deformation. Since mechanical deformation and interlayer stress interaction directly influence the extrinsic ME effect, composite configurations between magnetostrictive and piezoelectric materials critically influence the energy conversion efficiency of ME composites, as also do the imposed mechanical boundary conditions (BCs). Here, we aim to identify the material configurations in the composites under different BCs, in order to maximize their ME effects. The problem is set up as optimization problems solved by a genetic algorithm while the required multiphysics simulation is performed by finite element analysis. For five major mechanical BCs, we determined optimal ME laminate layer configurations and compared their magneto-electric conversion efficiency with that by typical sandwiched laminate composites. We also investigated how much the efficiency can be increased if arbitrary-arranged material distributions are allowed. The present study is expected to provide useful guidelines for the design of ME composites, and offers the possibility of finding new ME composite structures.