Numerical investigation of tensile response of notched bulk metallic glass composite specimens

Abstract

In this work, plane strain finite element and atomistic simulations of tensile response of double edge notched bulk metallic glass composite (BMGC) samples are conducted. A special constitutive model is used to represent the response of the bulk metallic glass matrix along with J 2 flow theory of plasticity to characterize the crystalline dendrites in the former, while a CuZr based glass matrix containing single crystal Cu dendrites is modeled in the latter. It is found that the ratio of notch root radius to the distance between the notch tip and the nearest dendrite, R/l 1, is an important parameter that governs the plastic deformation behavior and possible failure mechanisms. Both finite element and atomistic analyses show that as R/l 1 increases from a small to moderate value, a transition occurs in plastic flow through multiple shear banding with deflection by dendrites to ligament necking. On further increase in the above notch acuity parameter, the deformation behavior again changes to multiple shear banding without much hindrance from dendrites. Specimens with moderately blunt notches (as characterized by the value of R/l 1) having high hardening elongated dendrites exhibit pronounced plastic deformation along the ligament resulting in necking. The influence of BMGC microstructure and hardening of dendrites is also investigated from the finite element analyses.

Severe deformation-induced microstructural heterogeneities in Cu64Zr36 metallic glass

“…However, catastrophic failure at ambient temperature by forming penetrating shear bands limits their applications in structural and functional materials [8][9][10]. Although numerous strategies have been proposed to improve the ductility of MGs, brittle fracture is still a significant problem [11][12][13][14][15][16][17][18]. The energy of MGs is metastable and can be adjusted by external conditions, such as aging and rejuvenation.…”

The effects of alloying composition on plasticity and strength of notched metallic glasses

“…The design of specific sample configurations such as the introduction of notches is one of the main processes inducing the high plasticity and the superior strength in the MGs. [16][17][18][19][20] It is suggested that the notch in the MG samples can reduce the stress concentration and enhance the homogenous plasticity. 21 Furthermore, submicron notch MGs have the potential to be used in electronic devices and micro-electromechanical systems.…”

Special Hook Design for Hatch Cover Stocking Gantry Crane, Strength, Numerical Analysis under Static Loading

“…Stacking hatch covers is used especially in European countries and in our country [3]. During loading and unloading operations, accidents and permanent damages occur due to ignoring limit values and violating the standard rules [4]. As a result of the accident analysis, the need to review international rules and design criteria was emphasized [3,4].…”

“…Before steel hatch covers became widely used, until about the 1940s, wooden covers were used and covered with tarpaulin to ensure waterproo ng [1,3,4]. In this context, Maritime Transport in the 21st century is the most used transport route, where 80% of World Trade occurs [5].…”