SU1427228A1 - Tubular specimen for estimating strength of material - Google Patents

Abstract

This invention relates to shear testing. The aim of the invention is to improve the accuracy by bringing the test to the conditions of pure shear. Between the gripping parts 1 of the sample there is a cylindrical working part having two symmetrical transverse nadreea, two pairs of slits 4, 5 and 6, 7 located symmetrically relative to the axis 8. Radial forces are applied to the gripping parts 1 and create in sections through cuts, a tight state close to pure shear. 3 il.

Description

 -one

WITH

C) /

The invention relates to equipment for testing the strength of Materials and can be used to evaluate the strength characteristics of materials on shear.

. The purpose of the invention is to improve the accuracy by bringing the tests to the conditions of pure shear.

Figure 1 is a schematic representation of a tubular sample for assessing the strength of a material; figure 2 - section aa in figure 1; on fig.Z - section bb in figure 1.

The sample contains gripping parts 1, the working part located between them, executed in the form of a cylinder having two symmetrical transverse notches 2 and 3 located in the same plane, two pairs of slits 4, 5, and 6, 7 located symmetrically with respect to axis 8. One ends of the slits 4, 5 and 6, 7 lie on opposite edges of the sample, and others are connected to notches 2 and 3.

A tubular specimen for evaluating the strength of the material works as follows.

Radial forces of their mutual displacement are applied to gripping parts 1. As a result, in the sections of the sample passing through the cuts 2 and

4-x}

eight

3, the stressed state approaches a pure shear. In this case, the destruction of the sample is localized in these sections due to the presence of slots 4, 5 and 6, 7.

The accuracy of the assessment of shear strength is enhanced by localizing the zone of destruction and bringing the stress state to pure shear.

Claims (1)

Invention Formula A tubular specimen for assessing the strength of a material containing gripping parts, an interposed working part between them, having two slots in planes perpendicular to the axis of the specimen, one end of which lies on opposite edges of the specimen, characterized in that in order to improve accuracy by approximating the tests to the conditions of pure shear, the sample is made in the form of a cylinder having two symmetrical transverse notches located in the same plane, and an additional two cuts, made similar to the main one and axisymmetrically, and the ends of each notch are connected to the other ends of the corresponding slits.