Tailoring orthotropic mechanical and thermal properties in nonlinear contact, vibration and thermal problems via kriging-based optimization

Customizing suitable material properties for specific applications is always fascinating but challenging for designers, especially for problems with strong nonlinearities. Efficient and universal methods for tailoring material properties to meet required performances in nonlinear scenarios are still needed. Here, a generalized two-stage adaptive optimization method for tailoring mechanical and thermal properties is proposed. Properties including Young's modulus, Poisson's ratio, shear modulus, yield behavior, thermal conductivity and thermal expansion factor are involved and considered orthotropic. Spearman correlation coefficient analysis is carried out in the first stage to identify properties sensitive to the performances of interest. Adaptive optimization that combines multi-objective genetic algorithm and Kriging response surface is followed, and values of these sensitive properties are determined. Applications of the proposed adaptive material properties tunning method to nonlinear contact, vibration and thermodynamics problems are presented, respectively. It turns out adjusting material properties can significantly improve the contact stress distribution of bolted structure, depress the vibration of rotor system, and reduce the thermal expansion deformation of chip.