SU1665270A1

SU1665270A1 - Flat symmetrical specimen for tensile testing of sheet materials

Info

Publication number: SU1665270A1
Application number: SU894664082A
Authority: SU
Inventors: Юрий Георгиевич Важенцев
Original assignee: Ставропольский политехнический институт
Priority date: 1989-03-21
Filing date: 1989-03-21
Publication date: 1991-07-23

Abstract

Изобретение относитс к испытательной технике и может быть использовано дл испытани листовых материалов на раст жение. Цель изобретени - повышение информативности испытаний за счет обеспечени возможности определени полных диаграмм пластического деформировани в услови х совместного действи раст жени и сдвига при проведении испытаний на машинах различной податливости. Плоский симметричный образец состоит из торцовых захватных частей 1 и 2 и рабочей части 3 с равноотсто щими от торцов образца равномерно расположенными одинаковыми симметричными сквозными прорез ми 4 в виде пр моугольников со скругленными углами, ориентированных большей стороной вдоль оси симметрии образца, совпадающей с направлением нагружени образца усили ми P при испытании. На противоположных широких гран х центрального участка 7 между прорез ми 4 выполнены два симметричных надреза, наклоненных под острым углом к продольной оси образца. Размеры образца выбраны из условий, приведенных в тексте описани . 2 ил.The invention relates to a testing technique and can be used to test sheet materials for stretching. The purpose of the invention is to increase the informativeness of the tests by making it possible to determine the complete plastic deformation diagrams under the conditions of the joint action of tension and shear when testing on machines of various compliance. The flat symmetric sample consists of the end gripping parts 1 and 2 and the working part 3 with uniformly spaced equally symmetrical through slots 4 in the form of rectangles with rounded corners, oriented with the larger side along the axis of symmetry of the sample, coinciding with the direction of loading of the sample. force p under test. On opposite wide faces of the central section 7 between the slits 4, two symmetrical notches were made, inclined at an acute angle to the longitudinal axis of the sample. Sample sizes are selected from the conditions given in the description text. 2 Il.

Description

Изобретение относитс к испытательной технике и может быть использовано дл испытани листовых материалов на раст жение .The invention relates to a testing technique and can be used to test sheet materials for stretching.

Цель изобретени - повышение информативности испытаний за счет обеспечени возможности определени полных диаграмм пластического деформировани в ус- л,ови х совместного действи раст жени и сдвига при проведении испытаний на машинах различной податливости.The purpose of the invention is to increase the informativity of the tests by making it possible to determine the complete plastic deformation diagrams in the conditions of, the joint effect of tensile and shear during testing on machines of various compliance.

На фиг.1 изображен образец дл испытани ; на фиг.2 - сечение А-А на фиг.1.Figure 1 shows a sample for testing; figure 2 - section aa in figure 1.

Плоский симметричный образец состоит из торцевых захватных частей 1 и 2 и рабочей части 3 с равноотсто щими оттор- иев образца одинаковыми симметричными сквозными прорез ми 4 (на фиг.1 Показаны две прорези) в виде пр моугольников со скругленными углами. Прорези 4 ориентированы большей стороной вдоль оси симметрии образца, совпадающей с Направлением нагружени образца усили ми Р при испытании. На противополож- Йых широких гран х 5 и 6 центрального участка 7 между прорез ми 4 выполнены два симметричных надреза 8 и 9, наклоненных под острым углом Ф к Продольной оси образца.The flat symmetric pattern consists of end gripping parts 1 and 2 and the working part 3 with equally symmetrical through slits 4 equally separated from the sample (two slits are shown in the figure) in the form of rectangles with rounded corners. The slits 4 are oriented with a larger side along the axis of symmetry of the sample, which coincides with the direction of loading of the sample with forces P during the test. On the opposite wide edges x 5 and 6 of the central section 7 between the slits 4, two symmetrical notches 8 and 9 were made, inclined at an acute angle of Φ to the longitudinal axis of the sample.

Размеры образца выбраны из условийThe sample sizes are selected from the conditions

показана)до полного разрушени центрального участка 7, поскольку высвобожд юща- с энерги упругого деформировани поглощаетс пластически деформирующи- мис периферийными участками 10 и 11 при проведении испытаний на машинах различной податливости.shown) until the central section 7 is completely destroyed, since the release of the elastic deformation energy is absorbed by the plastically deforming peripheral sections 10 and 11 when tested on machines of various compliance.

Claims

Invention Formula

Flat symmetrical sample for testing sheet materials for stretching, consisting of end gripping parts and working part with equal symmetrical through slots in the form of rectangles with rounded corners, oriented with a larger side along the symmetry axis of the sample, differing from the ends of the sample. the fact that, in order to increase the informativeness of the tests by providing the possibility of determining the complete plastic deformation diagrams under the conditions of the joint action of stretching and shifting hectares when testing on machines of various compliance, on opposite wide edges of the central section, two symmetrical notches were made between the slits, inclined at an acute angle to the longitudinal axis of the sample, and

sample sizes are selected from conditions

h Н | (3 sin2 Ф + 0.75 cos2 Ф

ab | 7z1n2F + 0.75co82F l (3 ... 5) h;

a (10 ... 15) hsin Ф |; 2b and Opt / (ob - 0pts); L L Ip E / o,

where h is the thickness of the sample in the area of the incisions; H is the thickness of the sample outside the area of the incisions;

oNz- limit of proportionality of the material;

ob - conditional tensile strength of the material;

I is the width of the cuts;

a is the distance between the nearest edges of the longitudinal slits;

b is the distance from the edge of the sample to the nearest edge of the longitudinal slot;

L is the length of the longitudinal slits;

D Ip is the total elongation of the central working area at the stage of growth of the macrocrack of destruction in the area of notches;

E j Young's modulus.

In the process of loading with forces P, such a choice of sizes ensures, at the appearance in the zone of notches 8 and 9 of destruction, stable slow growth of the crack (not

h H

Ops 3 sin2 F + 0.75 cos2 F 7z1p2F + 0.75co52F

Oh

I (3 ... 5) h;

a (10 ... 15) h sin | F |; 2b and ots / (ob - G7PTs); L Д1Р Е / оь,

where h is the thickness of the sample in the area of the incisions;

H is the sample thickness outside the notch area;

Opt - the limit of proportionality of the material;

ob - conditional tensile strength of the material;

F is the angle of inclination of the flat cuts to the longitudinal axis of the sample;

I is the width of the flat cuts;

a is the distance between the nearest edges of the longitudinal slits;

L is the length of the longitudinal slits;

D Ip - “full lengthening of the central working area at the stage of growth of fracture macrofissures in the zone of inclined cuts;

E is Young's modulus.