Extension of the Equivalent Material Concept to Compressive Loading: Combination with LEFM Criteria for Fracture Prediction of Keyhole Notched Polymeric Samples

Abstract

This work analyzes, both theoretically and experimentally, the fracture process of square specimens weakened by keyhole notches and subjected to compressive stresses. Two materials are covered: general-purpose polystyrene (GPPS) and poly(methyl methacrylate) (PMMA). Firstly, the load-carrying capacity (LCC) of the specimens is determined experimentally. Then, by using the equivalent material concept (EMC) for compressive conditions coupled with the maximum tangential stress (MTS) and the mean stress (MS) criteria, the LCC of the notched specimens is predicted. The results show that by using the approach proposed in the present investigation, not only can the critical loads in the keyhole notched polymeric specimens be precisely predicted, but also the corresponding compressive critical stress of the two mentioned polymers can be successfully estimated.

Fracture assessment of inclined double keyhole notches in polylactic acid specimens fabricated by fused deposition modeling and traditional method

“…9 Materials with brittle or quasi-brittle behavior, like most polymers, require more attention because fractures in these materials usually occur suddenly. 10 Different criteria have been proposed for the fracture assessment. The most known criteria are the cohesive zone model, strain energy density (SED), J-integral, and the modified maximum tangential stress (MTS) criterion.…”

“…Each structural element is usually affected by different types of notches, such as U‐Notch, V‐Notch, or keyhole notch, which can weaken structural strength due to stress concentration at the notch tip 9 . Materials with brittle or quasi‐brittle behavior, like most polymers, require more attention because fractures in these materials usually occur suddenly 10 . Different criteria have been proposed for the fracture assessment.…”