Compact forced simple-shear sample for studying shear localization in materials

Abstract

A new specimen geometry, the compact forced-simple-shear specimen (CFSS), has been developed as a means to achieve simple shear testing of materials over a range of temperatures and strain rates. The stress and strain state in the gage section is designed to produce essentially "pure" simple shear, mode II in-plane shear, in a compact-sample geometry. The 2-D plane of shear can be directly aligned along specified directional aspects of a material's microstructure of interest; i.e., systematic shear loading parallel, at 45 degrees, and orthogonal to anisotropic microstructural features in a material such as the pancake-shaped grains typical in many rolled structural metals, or to specified directions in fiber-reinforced composites. The shear-stress shear-strain response and the damage evolution parallel and orthogonal to the pancake grain morphology in 7039-Al are shown to vary significantly as a function of orientation to the microstructure.

Fracture Characterization of Rolled Sheet Alloys in Shear Loading: Studies of Specimen Geometry, Anisotropy, and Rate Sensitivity

“…Often, the shear response of ductile materials is determined by conducting torsion tests on thin walled tubular samples [4][5][6][7] or using a compact forced-simple-shear specimen for bulk materials [8]; however, such tests are not suitable for sheet materials. Iosipescu [9] designed one of the first methods for the shear testing of sheet materials by using notched specimens subjected to four-point bending.…”

Модификация Метода Кольского Для Определения Прочности Хрупких Материалов На Срез

“…-образец в виде пластины размещается между нагружающим стержнем и опорной трубкой, внутренний диаметр которой чуть больше диаметра стержня [2]; -образцы специальных конфигураций размещаются в системе РСГ между плоскими торцами мерных стержней [3,4], что вызывает опреде-ленные трудности при изготовлении образцов.…”

A New S-Shape Specimen for Studying the Dynamic Shear Behavior of Metals

“…Different test apparatuses, such as split Hopkinson bar [9], gas gun [10], drop-weight test [11], and uniaxial hydraulic apparatus have been used for this purpose. Meanwhile, different geometries, such as torsional sample [12], sheet sample [1], flat or cylindrical hat-shaped sample [13,14], shear compression specimen [15][16][17], double shear sample [18], compact forced simple shear sample [19], and single-or double-edged sample [11] were used in these techniques. Among these specimens, shear deformation is constrained in specific sections because of their geometrical discontinuities.…”

“…The new S-shaped specimen geometry can be used to study the dynamic shear behavior of various metals.Metals 2019, 9, 838 2 of 17 force equilibrium [11]. Thus, the calculated shear stress-strain from this geometry is a rough estimate and inaccurate [19,23]. In addition, the shearing region rotates during testing due to the overlapping nature of the shear area in this geometry.…”

“…However, this sample design does not constitute a 'simple' shear loading stress state within the gauge section but a rather three-dimensional stress state. Moreover, this geometry leads to a radial inertial effect of the sample motion under dynamic loading [19]. Recently, Xu et al [11] proposed a new double side sample to study the shear band.…”