ESTIMATED EVALUATION OF THE SOFTENING KINETICS OF LAMINATES BASED ON STOCHASTIC MICRO-MESO MODELING

Abstract

Composite materials are widely used in modernindustry (aircraft and automobile manufacturing, construction, etc.). Present-day high-strength and lightweight composite materials, such as glass, carbon or organoplastics, exhibit elastic and strength anisotropy and deform nonlinearly at high stresses. Also, such materials have relatively small failure strain in comparison with metals, and they are significantly more expensive than steel and aluminium alloys. The most important task in the design of structures made of composite materials is the minimization of its mass without loss of strength properties. 

We developed a C # code which allows us to create finite element models of a unidirectional
fiber-reinforced composite material with randomly arranged straight-line fibers. By specifying
the input parameters (the dimensions of layers and fibers in the 90° layer) it is possible to simulate a composite material with [0°/90°/0°] laying.The software package produces a text file with the *.lgw extension, which is used in further numerical calculations.
In the second part of the article, we presented the method for modeling a unidirectional fiberreinforced composite with randomly arranged rectilinear fibers at the micro- and meso-level. These two approaches were compared on the problemof the composite panel stretching. The selection of the mesomodel mechanical characteristics was based on data of the micro-level model. In the mesomodel, the damage accumulation of middle layer (90° layer) was simulated using the Stochastic Failure criterion (random Mott scatter of strength properties). The calculated curves and data, obtained in micro- and mesomodels, correlate well with each other.