4 results about "Large deflection" patented technology

The present application relates to a kind of pre-tensioned steel wire rope lateral impact response calculation method considering geometric and friction nonlinear coupling.First, the linear tensile constitutive model of pre-tensioned steel wire rope is constructed, Von Kármán large deflection theory is introduced, and the geometric hardening relationship of the nonlinear growth of axial tension with lateral deflection is established;Subsequently, a bilinear bending stiffness model is constructed to calculate the critical anti-sliding torque that evolves dynamically with tension;Based on the principle of energy conservation and Rayleigh-Ritz method, the system total potential energy functional of axial tensile potential energy and nonlinear bending potential energy is constructed, and the maximum impact deflection and tension response of the steel wire rope are obtained by solving the energy residual equation, the maximum response is substituted back into the constitutive equation, and the maximum nominal stress of the midspan cross section, the maximum axial tension and the extension length of the internal slip zone are calculated.The present application has very high calculation efficiency compared with full-size finite element simulation, and is suitable for the rapid design and safety evaluation of steel wire rope protection system.

The application discloses a strain sensor calibration device with a limiting structure and a calibration method, and belongs to the technical field of measuring instruments. The calibration device comprises a vibration isolation platform, a clamping support beam fixed on the vibration isolation platform, upper and lower limiters symmetrically arranged above and below a cantilever beam, and the cantilever beam with one end connected with a piezoelectric ceramic exciter through a thread and the middle part clamped by the limiter. The piezoelectric ceramic exciter penetrates through the clamping support beam and applies displacement excitation with a preset amplitude and frequency to excite the cantilever beam to vibrate. When the deflection of the short beam section of the cantilever beam exceeds the set gap, the limiter is in contact with the short beam section, the nonlinear modulation effect is used to suppress the subharmonic vibration and chaotic motion of the short beam section, so that the main beam section outputs stable periodic deflection response. The application solves the problems of unstable signal and insufficient precision in dynamic calibration, and realizes high-precision dynamic calibration of the strain sensor under the condition of low frequency and large deflection.

This invention relates to the field of motor control, and more particularly to a positioning and calibration method for a gantry mechanism of a bonding machine based on solder joint alignment. The method includes: monitoring the speed difference and real-time displacement deviation of two independently controlled servo motors on both sides of the gantry mechanism; calculating the predicted displacement deviation on both sides of the gantry mechanism based on the speed difference and real-time displacement deviation; calculating the deflection angle of the gantry mechanism's crossbeam relative to the guide rail length direction based on the predicted displacement deviation; determining the target speed of the two servo motors based on the deflection angle; and determining the change process of the current speed towards the target speed. This invention utilizes the length of the crossbeam to ensure that the generated corrective torque is physically matched with the required angular deviation; it can automatically plan a smoother speed change rate under high-risk conditions with relatively large deflection angles; and it employs a relatively fast speed change process under normal fine-tuning conditions with relatively small deflection angles, thereby ensuring the system's rapid response capability to minor disturbances.

The present application relates to the technical field of buckling and post-buckling analysis, and particularly relates to a method for explicit fast analysis of buckling and post-buckling under mechanical load, which simultaneously considers the influences of pre-buckling nonlinear deformation, post-buckling large deflection, initial geometric defects and the influences of the positions of the stiffeners in space. Based on high-order shear deformation theory, the influences of precise curvature relationship are considered, and control equations for buckling problems of a stiffened composite cylindrical shell structure are established, wherein the control equations contain tensile-bending coupling effect, tensile-twist coupling effect, bending-twist coupling effect and thermal effect. The method introduces precise curvature expression, geometric nonlinear relationship and the relationship between the stiffened structure and the coordinate position of the shell into the buckling and post-buckling analysis of the fiber-reinforced anisotropic stiffened laminated cylindrical shell under axial compression, external pressure and torsion working conditions, and can consider different combinations and distribution forms of the stiffeners.