ANSYS 非线性屈曲分析例子命令流

The first Equation is the Plastic strain equation:

Where the super script “pl” represents the plastic strain, and “el” represents the linear strain, and Ԑn is the original strain. To calculate the linear strain the following equation is used:

For this solution method, ANSYS uses the linear Eigenvalue method to solve for the buckling load. The Following is a command prompt used to run the Eigenvalue method on ANSYS.


ANSYS produces Favorable results for buckling Analysis. The non-linear Buckling analysis tends to give more conservative results as seen in the figures. Care must be taken, as sometimes non-linear problems may not converge.

It is important to understand what the NLGEOM command does, and how it does it. This command allows ANSYS to engage in a non-linear elastic modeling of the beam.

In the previous equation Represents the equivalent total strain measure and is calculated using the following equation:

As can be seen in the equation, as the number of iterations are increased, the magnitude of the plastic deformation decreases (in a new iteration, the results for the plastic strain is used as the initial strain). The rate of the decrease also decreases with an increasing number of iterations, until the answer for the strain converges. This however does not take into account Non-linear Young modulus, and more complicated methods must be used in order to compute the stress-strain of a model with a non-linear Young’s modulus.



ANSYS can also produce non-linear results. This is done by using sub-stepped loads, to calculate the strains and getting a new Young’s Modulus with the given strain. An initial deformation is placed in the model, so that ANSYS may bend the model and simulate buckling (otherwise the load would show only compressive results). The next is a command prompt to input in ANSYS to produce the analysis.
源自文库
Beams Rods Columns Crankshafts Piston and Cylinders Synthetic bones and prosthetics. Any mechanism that undergoes compression



Finite Element Analysis allows the Solution of buckling problems. The Column is divided into different nodes and a small preload is added. ANSYS offers 2 buckling modes, Eigenvalue (Linear) and a non-linear solution method.



Buckling is the failure of columns and rods when under a compressive load. The rod/column/beam bends before the load reaches the material’s yield point. Buckling occurs due to the structure’s imperfections.