SU1635047A1 - Method of evaluating material strength - Google Patents

Abstract

The invention relates to a testing technique and can be used to assess the strength of a structure. The purpose of the invention is to approximate test conditions to the operating conditions of sealing linings of protective coatings. Two samples were used, on which notches 2 and 3 were made. The samples are connected in parts from notches 2 and 3 to ends 5 and 6. A tensile load is applied between the inner edges of notches 2 and 3, as well as to the ends of 5 and 6 samples. 4il.

Description

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The invention relates to a testing technique and can be used to determine the strength of materials when combining tensile and a two-plane cut.

The purpose of the invention is to bring the evaluation conditions closer to the operating conditions of the sealing claddings of protective reinforced concrete structures of energy-JQ objects 0

Fig. „1 is a diagram of the sample; in Fig. 2 - section A-A in Fig „1; on fig.Z - section bb in fig01; in Fig „4 - section B-B in Fig„ K15

The method is implemented as follows

On opposite wide faces of the prismatic sample 1, symmetrical cuts 2 and 3 are made, 2Q cloned at an angle about the longitudinal axes of the specified faces. Cuts 2 and 3 are symmetrical to each other relative to the plane passing through the edges of these cuts that lie on narrow 25 faces of sample 1 "The latter is rigidly connected to an identical sample 4, and the connection (for example, gluing) is carried out in the areas between the aligned edges of the notches ™ 2 and 3 and the ends 5 and 6 of samples 1 and 4" that are closest to these edges Between the inner hem E notches 2 and 3 to the samples 1 and 4 are attached to rods 7 and 8, the heads 10 and the edges 9, koto- Vr ryh bonded along the full length slits 2 and 3, with their edges "

The loading of samples 1 and 4 is carried out in two directions: along the length of the axial axis of samples 1 and 4 combined with each other (force P) and along the axis of the tons 7 and 8 (force S). From the force P in the working sections x with notches 2 and 3, stresses appear (j and Ј, acting in the planes of samples 1 and 4. "From the force S of these cross sections, shear stresses Јg in the direction perpendicular to the direction of action stresses Ј, to the planes of samples 1 and 4 "With joint loading by forces P and S in sections with notches 2 and 3 single Voltages (J, Ј (and C2, i.e., a combination of stretching and a two-plane cut is realized) operate in a temporary manner. The ratio between these voltages is varied by changing the values of P and So

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Making additional cuts 3 in the sample, symmetrical to cuts 2 relative to the plane passing through the edges of cuts 2 and 3 and perpendicular to the sample axis, is necessary to provide a closed symmetric contour that is used to mount the heads 9 and 10 tons of 7 and 8 "Compound sample 1 with an identical sample 4 in the areas between the aligned edges of the notches 2 and 3 and the ends 5 and 6 of samples 1 and 4 and attaching two symmetric t 7 and 8 to the samples 1 and 4, the edges of the heads 9 and 10 of which are connected along the entire length of the notches 2 and 3 with their kro The device provides the possibility of transferring to the working sections with notches 2 and 3 of the section in the plane of the samples (voltage что4), which, with the biaxial stress of samples 1 and 4 with the forces P and S, allows to create in the working sections a stress biaxial slice and thereby expand the possibilities of testing about

Attaching samples 1 and 4 to each other only in the areas between the outer edges of cuts 2 and 3 and the ends 5 and 6 of the sample ensures freedom of deformation of the central zone of the sample (т0е0 zone between cuts 2 and 3) from the forces So

The use of the invention allows the evaluation of the strength of products (primarily from sheet materials) under complex stress conditions, including the combination of stretching with a two-plane cut, which increases the reliability of elements whose dangerous sections work under the specified stress state. namely, the sealing facings of protective reinforced concrete structures of energy facilities.

Claims (1)

Invention Formula The method of assessing the strength of the material, according to which, on opposite wide faces of a prismatic sample, at an acute angle to their symmetrical axes, two symmetrical with respect to the indicated axes and a plane equidistant from the wide edges are cut and the sample is axially distal load.to his rashrusNIL h a over the cross section with u n and and with on-fezami, tl and - by the fact that, in order to approximate the conditions for evaluating the k conditions of operation of the sealing linings of protective reinforced concrete structures of energy facilities, additional cuts are made in the sample, symmetrical to the first with respect to the plane passing through the edges of the cuts and perpendicular real axis about The sample, a sample is rigidly connected by a wide edge with an identical sample in the areas between the combined edges of the incisions and the ends of the samples closest to them, and additional tensile load is applied to the areas of wide edges between the incisions in the direction perpendicular to the main one. Fm.4