6 results about "Hoop strain" patented technology

The present application relates to the technical field of tunnel construction, and particularly relates to a pile foundation response test method under a double-line tunnel shield side-penetration working condition. Residual strain is obtained after the first tunneling body passes and rests until the end, and the stiffness attenuation rate at each depth is calculated according to the attenuation linkage ratio; when the second tunneling body passes from the other side, the cumulative axial strain and the cumulative hoop strain are obtained by merging the stiffness attenuation rate as the weight, the real-time axial and hoop strain and the residual strain at each depth, and the cumulative plastic strain, the cumulative settlement and the bottom interface stiffness are calculated accordingly, so that the quantitative characterization of the pile body deformation and the internal force distribution evolution law in the whole double-line construction process is realized.

The present invention provides a bellows forming springback control method and mold based on stress regulation, relating to the field of metal processing technology. The method comprises obtaining an expression for the circumferential strain increment based on the principle of material bending deformation; simultaneously establishing an expression for the plastic strain increment, a plastic stress differential equation, and an expression for the circumferential strain increment to obtain an expression for the relationship between the circumferential stress and the axial stress; and, based on the expression for the relationship between the circumferential stress and the axial stress, obtaining a relationship curve with the circumferential compression strain as the independent variable and the ratio of the axial stress to the stress before compression as the dependent variable. After the tube is bent and deformed, the trough can be moved radially toward the axis of the tube along the radial direction of the tube to achieve radial contraction of the trough, thereby increasing the circumferential stress of the trough and reducing the axial stress difference between the inner and outer surfaces, thereby reducing the axial stress of the bellows and effectively controlling the axial springback of the bellows.

The invention provides a resistance-type flexible film strain test and calibration method for a special-shaped structure. The method comprises the following steps: integrating a resistance-type flexible film strain test unit along the curved surface of a calibration piece of the special-shaped structure; applying an internal pressure load to the special-shaped structure calibration piece to obtain a resistance variable quantity and an annular strain; the internal pressure load is changed, the corresponding resistance variation is measured, the corresponding circumferential strain is calculated, and the corresponding relation between the internal pressure load and the corresponding resistance variation is established; calculating the sensitivity coefficient of the resistive flexible film strain test unit on the special-shaped structure calibration piece; integrating a resistance-type flexible film strain test unit on the annular curved surface of the special-shaped structure test piece, applying an internal load, and measuring the resistance variation; and selecting a corresponding sensitivity coefficient according to the curvature radius and the internal load, and calculating the actual strain. According to the resistance-type flexible film strain test and calibration method provided by the invention, the problem of insufficient acquisition of special-shaped structure strength test strain data caused by difficulty in arranging a conventional resistance strain sensor on a small-curvature radius special-shaped structure is solved.

The present application relates to the technical field of tunnel construction, and particularly relates to a pile foundation response test method under a double-line tunnel shield side-penetration working condition. Residual strain is obtained after the first tunneling body passes and rests until the end, and the stiffness attenuation rate at each depth is calculated according to the attenuation linkage ratio; when the second tunneling body passes from the other side, the cumulative axial strain and the cumulative hoop strain are obtained by merging the stiffness attenuation rate as the weight, the real-time axial and hoop strain and the residual strain at each depth, and the cumulative plastic strain, the cumulative settlement and the bottom interface stiffness are calculated accordingly, so that the quantitative characterization of the pile body deformation and the internal force distribution evolution law in the whole double-line construction process is realized.

The present application relates to the technical fields of strain measurement, in particular to a device for measuring the micro hoop strain of a concrete cylinder specimen. In order to solve the problem that the existing method for measuring the micro hoop strain of a specimen is difficult to test the micro hoop strain of the specimen, a new device for measuring the micro hoop strain of a concrete cylinder specimen is provided, which comprises a first arc-shaped frame and a second arc-shaped frame, and the first arc-shaped frame and the second arc-shaped frame are both provided with a hoop support part, the two hoop support parts are symmetrically distributed left and right, the front end of the first arc-shaped frame is fixed with a first extension part, the front end of the second arc-shaped frame is fixed with a second extension part, a clamping spring is arranged between the first extension part and the second extension part, the left side of the second extension part extends leftward with a connecting part, the connecting part is fixed with a supporting leg, and the connecting part is also fixed with a displacement sensor. The device has simple structure, low manufacturing cost and is convenient to use.

The invention relates to a wrapping assembly for a porous fractured rock sample in a flexible loading mode and an annular strain correction method. The sample assembly comprises a rock sample, end plugs arranged at the two ends of the rock sample, a self-adaptive wrapping film wrapping the peripheral side of the rock sample, and a heat shrink tube wrapping the peripheral sides of the end plugs and the self-adaptive wrapping film; the self-adaptive wrapping film is formed by arranging at least one piece of Kevlar high-strength cloth and at least one piece of Kevlar high-elasticity cloth along the peripheral side of the rock sample at intervals; and the adjacent Kevlar high-strength cloth and Kevlar high-elasticity cloth are spliced. According to the wrapping assembly for the porous fractured rock sample in the flexible loading mode and the circumferential strain correction method, a self-adaptive wrapping film is adopted, and test failure caused by high confining pressure extrusion penetration damage of a heat shrink tube is avoided; self-adaption to rock circumferential expansion deformation is achieved, and the stability of flexible loading load is maintained; the provided strain correction method ensures the accuracy of circumferential strain measurement; the hollow pressing buckle provides installation positioning for the acoustic emission probe, and the stability of monitoring signals is maintained.