Effect of elastic property variations on the stress-strain state calculation of a structure

Abstract

Aluminium alloys are key materials in the aerospace industry because of their combination of low density, high specific strength, and excellent corrosion resistance. Metals are generally considered isotropic materials, exhibiting uniform mechanical properties in all directions. However, plastic deformation processes, such as rolling, can induce texture formation, whereby crystallographic grains align along the direction of deformation. This leads to planar anisotropy, which significantly affects the mechanical behavior of the material under service loads. This study investigates how variations in elastic properties – Young's modulus E and Poisson's ratio μ – affect the stress–strain state (SSS) of a 1163 ATB aluminium alloy sheet structure. A literature review was conducted on analyze the effect of anisotropy on the mechanical properties of specimens cut at various angles to the rolling direction. This confirmed the dependence of the elastic parameters on the orientation. This study presents laboratory test results for Poisson’s ratio in the longitudinal and transverse directions. The experimental data obtained were implemented in finite element modelling to assess the influence of anisotropy on the stress and strain distribution in typical thin-walled structural elements. Modelling was performed using a simplified geometry – a rectangular plate with boundary conditions that simulate real service loads. Nine combinations of elastic parameters were considered to evaluate the sensitivity of the calculated results to variation in these parameters. The analysis revealed that slight changes in the elastic properties can result in significant deviations in SSS, especially in the stress concentration zones. Such deviations considerably impact the assessment of the structural components’ residual strength and durability. Therefore, accounting for anisotropic behavior is critical for improving the accuracy of engineering calculations, particularly in strength and life assessment tasks. Therefore, accounting for anisotropic behavior is critically important to improve the accuracy of engineering calculations, particularly in tasks involving strength and life assessment. The obtained results are recommended for use in modelling, designing, and verifying aerospace components.