The objective of this article is to present an algorithm for moment evaluation and probability density function approximation of performance function for structural reliability analysis. In doing so, a point estimation method for probability moment of performance function is discussed at first. Based on the coherent relationship between the orthogonal polynomial and probability density function, formulas for point estimation are derived. Vector operators are defined to alleviate computational burden for computer programming. Then, by utilizing C-type Gram-Charlier series expansion method, a procedure for probability density function approximation of the performance function is studied. At last, the accuracy of the proposed method is demonstrated using three numerical examples.

We demonstrated the desirable microwave absorption properties in a 3D Ni@C/polystyrene (PS) sphere metacomposite, originated from the electromagnetic transform between the permittivity and the permeability. The metacomposite is composed of an array of millimetric PS spheres coated by highperformance Ni@C nanocapsule microwave absorbents. Such a phenomenon is caused by the nearfield electromagnetic interaction, modeled by a theoretical simulation, resulting in the reciprocal resonances for the dielectric and magnetic loss factors. The resonance frequencies are proportional to the PS sphere size. This study provides a bottomup strategy to fabricate the metacomposite and meanwhile has important implications in understanding the electromagnetic transformation.