Self-tightening circular tube circumferential tensile test device for maintaining curvature of circular tube for pressure testing machine

Abstract

The invention provides a self-tightening circular tube circumferential tensile test device for maintaining the curvature of a circular tube for a pressure testing machine. The device comprises a horizontal loading platform, a plurality of separation discs circumferentially and uniformly distributed on the loading platform, and a conical loading head positioned in the middle portion, the outer walls of the separation discs are arc-shaped, the upper sections of the inner walls of the separation discs are provided with internally tangent curved inclined surfaces matched with the conical outer peripheral surface of the conical loading head, the joint sections of the lower ends of the inner walls of the separation discs and the curved inclined surfaces are vertical arc sections, the multiple separation discs are independent of one another, the spliced separation discs form a cylindrical whole and are arranged in the circular pipe, and when the conical loading head moves downwards, the sidefaces make contact with and are attached to the curved inclined surfaces on the inner surfaces of the separation discs and move relatively to push the separation discs to move outwards in the radial direction away from the center of the circular pipe. According to the invention, the test range of the annular tensile test of the pipe is widened; the curvature of the circular tube can be greatly kept in the circular tube circumferential stretching process, it is guaranteed that the circular tube is not affected by bending stress, and the measurement accuracy is guaranteed.

Description

technical field [0001] The invention belongs to the field of material performance test devices, and in particular relates to a self-tightening circular tube hoop tension test device for a pressure testing machine which maintains the curvature of the circular tube. Background technique [0002] Metal and composite small-sized round pipes, such as FRP (fiber reinforced plastic) pipes, need to use test molds such as separation discs to carry out pipe hoop tensile tests. [0003] The hoop tensile strength of the round tube is defined as the hoop strength of the round tube (also known as Hoop strength). The hoop tensile strength can be accurately measured by the internal pressure method. The internal pressure method is to seal both ends of the test pipe section, inject liquid into the pipe section, and then pressurize the liquid through a pressure pump until the sample is destroyed. The test device required by the internal pressure method is complex and has certain risks. [0...

AI Technical Summary

Problems solved by technology

The separation disc method cannot strictly stretch along the circumference of the tube, which will affect the accuracy of the measurement to a certain extent

Existing pipe hoop tensile tests use tensile testing machines. Compared with compression testing machines, tensile testing machines have disadvantages such as small measuring range and unstable tensile force measurement.

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