What Is a Shear Load?

The maximum shear stress of a rock against shear failure when subjected to shear is called shear strength. The shear strength of rock is the same as that of soil, and it is composed of cohesion and internal frictional resistance, but they are larger than soil, which is related to the strong connection of rock. ^[1]

Shear strength

Shear strength refers to the material's ability to withstand shearing forces, codename c, refers to the strength limit when the external force is perpendicular to the material axis and acts on the material under shear. The unit pressure in square millimeters is the shear strength. Divided in kilonewtons per unit area, kN / mm ² ;.

Shear strength is the ability of a material to withstand shear forces. The shear strength of a stainless steel composite plate refers to the ability of the composite interface of two metals to withstand shear forces. The national standard (GB / T8165-2008) stipulates that the shear strength of stainless steel composite plate is 210MPa. In production practice, the shear strength of hot-rolled stainless steel clad plates can reach 345 MPa. The magnitude of the shear strength indicates the firmness of the bonding between the cladding and the base layer of the stainless steel composite plate. The stronger the bonding, the better the technical performance of the stainless steel composite plate. Therefore, shear strength is the most important technical index of stainless steel composite plate. In addition to shear strength, other mechanical properties of the stainless steel clad plate include: yield strength, tensile strength, elongation, impact performance, internal and external bending tests, etc.

Shear strength indicates the maximum breaking load per unit area of the adhesive when subjected to tangential stress. According to the way of stress, it can be divided into tensile shear strength, compressive shear strength, torsional shear strength, bending shear strength, etc. Among them, tensile shear strength is the most commonly used. The test specimen for measuring tensile shear strength is generally 12.5cm × 2.5cm × 1.6mm. Single-sided overlap is adopted, and the length of the overlap surface is about 12.5mm ± 0.25mm. After the test piece is subjected to surface treatment during the measurement, the adhesive is evenly coated on the test piece, and then the two test pieces are superposed and cured under prescribed conditions. The width of the two test pieces after being superposed does not exceed 0.5. mm. Load the test piece on a tensile tester at a constant tensile speed of 10 mm / min until the test piece adhesive layer is broken. Note the failure load on the dial of the testing machine, and calculate the shear strength (W) according to the following formula:

W = P / F = P / ab

In the formula, P is the failure load, N; F is the overlap area, cm2; a is the length of the overlap surface, cm; b is the width of the overlap surface, cm. There should be no less than five pairs of test pieces. The overlap area should be calculated based on the actual measured value after each pair of test pieces is broken, and the accuracy is 0.01cm2. For long-term adhesives at higher and lower temperatures, the strength at different temperatures should be measured. The usual test temperature is 60 ° C, 0 ° C, 60 ° C, 100 ° C, 150 ° C, 200 ° C, and 250 ° C. During the test, a heating or cooling device should be installed on the test machine. The test sample should be kept at the test temperature for 30 ~ 45min.

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