Localized forming limit analysis of substrate-supported metals: Influence of yield-dependent necking bound angle

Abstract

In this paper, the influence of functional elastomeric substrate-supported layers for enhancing potential resistance capability against localized plastic failure of advanced high strength steels is considered based on a localized necking model of vertex theory. Application of this structure leads to postponing the plastic instability of the metallic part. By defining diffuse and localized modes of deformation in a general framework, the theoretical models are developed to predict necking limits at several stress states. In addition, the results of the Hookean and neo-Hookean elastomers are compared in terms of strain hardening with the anisotropy parameter of Hill’s yield criteria. Since necking band angle (NBA) is a principal factor for the necking prediction, its effect on bifurcation events is evaluated specifically for different ratios of stress rate, and quadratic and non-quadratic yield criteria. This analysis is performed by proposing a supported and yield-dependent necking bound angle (YD-NBA). All considerations are done by providing equilibrium conditions governed over the NBA. Finally, obtained results indicate good agreements between several theoretical considerations and experimental data.

Forming limit diagrams and mechanical properties of AA1050/Ti CP2 multilayered composite produced by the accumulative roll bonding technique

“…37,41 As long as a higher number of ARB passes could be applied on metals, it is not unlikely to improve formability by ARB, as reported by other researchers. 37,41,[51][52][53] However, previous works were dedicated to mono-metallic materials, while the present research firstly characterized the formability of a bimetallic multilayer composite. Therefore, further investigations are needed to figure out governing mechanisms on formability.…”