Stress Distributions and Notch Stress Intensity Factors in Multimaterial V-notches Under Antiplane Shear and Torsion

TL;DR

This paper introduces a new theoretical method to analyze stress distributions and notch stress intensity factors in multimaterial V-notches, demonstrating significant reductions in stress concentrations and increased structural capacity through optimized material design.

Contribution

The work presents a novel closed-form solution for calculating stress and NSIFs in multimaterial V-notches, enabling design optimization to reduce stress concentrations and improve structural performance.

Findings

Significant reduction in NSIFs and stress concentrations achieved.

Structural capacity increased by up to 46%.

Nominal strain at failure increased by up to 86%.

Abstract

This study investigates how the insertion of multimaterial circular regions embracing the tip of a finite V-notch can be used to reduce the Notch Stress Intensity Factors (NSIFs) in structures subjected to antiplane shear or torsion. Towards this goal, this work presents a novel theoretical framework to calculate stress distributions and NSIFs in closed-form. Thanks to the new solution, it is shown that by tuning multimaterial region radii and elastic properties it is possible to significantly reduce the NSIFs and stress concentrations at the material interfaces. To investigate whether the proposed multimaterial system translates into increased structural capacity even in the presence of significant nonlinear deformations, computational simulations were conducted using nonlinear hyperelastic-damage and elasto-plastic-damage models. The preliminary results show increases of structural capacity up to 46% and of nominal strain at failure of up to 86% at the expenses of only a 8% reduction in structural stiffness. It is expected that a similar approach can be extended to other loading conditions (e.g. mode I and mode II, and fatigue) and that even larger gains can be obtained by performing thorough optimization studies.