From the angle critical force,this thesis analyses the stability of the formation of axle shaft spline in the extrusion and the calculation of the constraints available after losing stability.

First we suppose a deflection expression on principle of minimum potential energy for an opening elastic rectangular thin plate loaded with critical force, which can meet the side conditions of displacement or force.

The mathematical model, used to calculate the buckling critical force of compliant parallel four-bar mechanism with right-angle-notch flexure hinges, was established with the approximative differential equations of the flexible curve based on the bending theory in strength of materials.

The critical load of the pipe helical buckling, contact force distribution of pipe on the bore hole and the average side contact force of the pipe post buckling in the horizontal section of horizontal well are calculated by using the finite difference method and the Newton iteration method.

The shearing force is still on the critical load.

Based on the finite element method and the false structure method, this paper analyses and deduces the calculating method for the critical pressure of axil pressure members with lateral elastic supports.

Based of the equilibrium equations of clastic stability, the least critical pressure of open flexible noncircular cylindrical shells and plates of variable thickness with least squares points-fit of weighted-residual methods is calculated.

Improving buckling critical stress of sheet with the elastic pressure on the surfaces of sheet and it's application

The distribution of interior critical stress of different casings under different circumstances are analyzed by way of the establishment of nonlinear FEM,also the critical in-situ stress equations of different operating interior pressures are achieved.

In the paper,based on the governing equations of buckling,the buckling equation of anti-symmetrically laminated plate is established and the critical stresses are calculated under two-axial compressive loads in-plane.

New theory in the front of theoretical basis research of molecular thermodynamics 4: on molecular structure of organic compound and theoretical equation of critical pressure;

Prediction of the critical pressures of alkanes using a quantitative structure property relationship;

The critical pressure of two spans beams with one end fixed and the other hinge joined;

The curvature formula of tiny curved rod,together with the vector method of area,is applied to inference for Euler formula about critical load of slender compressive rod which one end is fixed and another is free.

And then,the equations are applied to inference for Euler formula about critical load of slender compressive rod with common constraints.

In elastic mechanics, it is common practice to calculate critical loads in buckle of thin plates by means of double triangle series.