SU1415134A1 - Method of fatigue tests of welded structure - Google Patents

Abstract

This invention relates to the field of fatigue testing of structures. The purpose of the invention is to increase the reliability of tests of a welded truss by taking into account the influence of the stress state of the lattice when bending the truss on fatigue of joints. The welded truss 1 cycle is compressed, preloading it with sa 2 different static axial forces, for example, one by stretching, others compression. As a result, a cyclic eccentric compression is created, imitating the bending of the truss, which makes it possible to take into account in testing the effect of the stress state of the lattice on the fatigue of the seams. 1 il. with

Description

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This invention relates to the field of fatigue testing of structures.

The purpose of the invention is to increase the reliability of the tests of the welded truss due to the influence of the stress: the state of the lattice during the bending of the truss: on the fatigue of the seams.

The drawing shows the device: for the implementation of the proposed method

: Welded truss 1 consists of four ipex 2 and lattices in the form of IKOCOB 3. At the ends of two 2, upper and lower 5 and 4 and 5 are complete, respectively, with grippers. The device contains a loading ring with cyclic compression (not shown) with grippers, surfaces 6 and 7 of which are designed to interact with points 4 and 5, respectively: 2. The device is equipped with upper 8 and lower 9 crossbars, which by means of axes 10 ball-and-low-sided links to support points 4 1 and 5 bearing pins 2 of test farm I “The right ends of the top 8 and bottom I 9 crossbars are connected (joined) I by means of a variable length link 11, one of the two of the two forks 12 with threaded shanks, a tension nut (which 13) and two lock nuts 14. The left ends of the crossbars are connected, for example, with a screw jack 15 fixed to the end of the console part of the lower cross member 9 and consisting of a base 16, a sliding screw 17 and lock nuts 18. Surfaces 6 and 7 have on one side of (right) exhibition wedges 19 with adjusting screws 20 to ensure the same conditions of interaction between n 4 and 5 with surfaces 6 and 7 of the grippers. Screw jack 15 and screw clamp 11 can be supplied with months doses (dynamometers) or strain gauges for monitoring

their stresses and efforts (not shown). Tensometric sensors (not shown) are glued to them to monitor the stresses and stresses in 2 of them. Instead of screw connections (stud 1 1 and jack 15) other static loaders, for example hydraulic cylinders, can be used.

The method is implemented as follows.

The clamp 11 and the jack 15 are loaded over the sa, the trusses with various static forces, for example, some compress themselves (closer to the stud 11), and others stretch (closer to the jack 15). The same cyclic compressive loads are applied to all the trusses themselves. The cyclic stresses created in the circuits are monitored with glued ones. these sensors. The creation by these operations of an eccentric cyclic loading of a truss makes it possible to imitate its work under conditions of cyclic compression with bending, which allows to take into account the effect of lattice stresses on the fatigue of welds. As a result of the tests, the farm life is determined by the accepted fatigue criterion.

Claims (1)

Invention Formula The method of testing fatigue welded structures, which consists in applying a cyclic compressive load with an operating amplitude of cycles to the structure and determining its durability, which is due to the fact that, in order to verify the reliability of the welded truss tests, influences of the stress state of the lattice during the bending of the truss on the fatigue of the seams, static axial loads of varying magnitude are applied to the trusses themselves, and the cyclic loads are also applied to these by themselves.