Two-scale concurrent topology optimization method of constrained layer damping structure subjected to non-uniform blast load

The constrained layer damping structure is used to resist the impact damage from blast load and furthermore the two-scale topology optimization of the damping layer can deduce the additional mass of micro damping material while satisfying the required objective for restraining impact response. However, in their optimization model, the non-uniform pressure of blast load is usually simplified into a concentrated or uniform load equivalently, for the thin-walled structure, it is necessary to regard the load as a non-uniform distribution. In this paper, in order to reveal the rule between blast load and optimization layouts, a concurrent topology optimization approach is proposed, where the non-uniform distribution of blast load is considered. Firstly, Arbitrary Lagrange-Euler method is used to obtain the blast load as an input condition of dynamic response. Then, the optimization process is applied by combining using the Precise Integration Method used to solve the dynamic response, an improved Adjoint Variable Method for sensitivity study, and Optimization Criterion method employed to update the design variables. In order to make sure both the micro-layouts and their distribution are optimized, the micro sensitivity depends on the vectors of element displacements affected by the different macro load forms. The results of numerical examples show that the non-uniform load has a notable influence on the shape and size of micro-topology layouts as well as the position of macro-reserved material.