Experimental and numerical investigation of model I dynamic fracture toughness of 95W-3.5Ni-1.5Fe alloy using the semi-circular bend specimens. (December 2021)

• Record Type: Journal Article
• Authors: Yang, Ziqing; Wang, Zhanjiang; Qin, Na
• Is Part Of: Engineering fracture mechanics. Volume 258(2021)
• Publication Date: 2021-12
• Subjects: Tungsten heavy alloys -- Dynamic fracture toughness -- Rate-dependent cohesive law -- Semi-circular bend -- Finite element analysis; Fracture mechanics -- Periodicals; Rupture, Mécanique de la -- Périodiques; Fracture mechanics; Periodicals; 620.112605
• DOI: 10.1016/j.engfracmech.2021.108053
• Languages: English
• ISSNs: 0013-7944

Abstract

Highlights: Obtaining the fracture toughness of 95W using the semi-circular bend specimens. A rate-dependent bi-linear cohesive law to describe the dynamic fracture of 95W. The dynamic fracture toughness of 95W increases with the increase of the strain rate. Abstract: Semi-circular bend specimens are used to measure the brittle materials' fracture toughness, such as brittle metals, rocks, and ceramic materials. The quasi-static and dynamic model I fracture toughness of tungsten heavy alloy, a typical brittle metal material, are measured using the semi-circular bend specimens under quasi-static compression and dynamic impact loadings. For quasi-static cases, the specimens are loaded on a universal testing machine with a constant loading speed. While for dynamic cases, the specimens are executed on a modified split Hopkinson pressure bar system with the impact pressures from 0.2 to 0.4 MPa. The results show that the dynamic fracture toughness of tungsten alloy increases with the increase of the loading rate. Further, a rate-dependent bilinear traction-separation law is introduced to explain the dynamic fracture behaviors of tungsten alloy. The parameters of the rate-dependent law are obtained from the experiments and the finite element simulations. Finally, the dynamic simi-circular bend simulations using the cohesive element with rate-dependent cohesive law are established to simulate the crack propagation, and the simulation results are in good agreement with the test data.