1: The concept of pressure rod stability
In material mechanics, to measure whether a component has sufficient bearing capacity, three aspects should be considered: strength, stiffness, and stability.
Stability - The ability of a component to maintain its original equilibrium state under the action of external forces.
The larger the Fcr, the less likely the rod will be unstable.
When the pressure is equal to the critical force:
The critical pressure is a definite value when the material, size and restraint of the strut have been determined. Therefore, it can be judged whether the pressure rod is stable or unstable according to whether the actual working pressure of the rod is greater than the critical pressure. The key problem to solve the stability of the pressure rod is to determine the critical pressure.
Two: the critical pressure of the slender pressure rod hinged at both ends
example:
Three: critical pressure of slender pressure rod under other bearing conditions
1: One end is fixed, one end is free
2: Both ends are fixed and one end is fixed and one end is hinged
3: Both ends hinged
Summarize:
Four: the scope of application of Euler's formula empirical formula
1: Critical stress
Introducing the inertial semi-longitude i and the flexibility λ
to obtain the expression of the critical stress
2: Euler's formula trial range
In tensile and compression experiments, we know that the material deforms when it is subjected to external force, and the property that the deformation completely disappears when the external force is removed is called elasticity.
And this is stability, σ p is the proportional limit.
σ s is the yield limit.
Summarize:
Five: more stable than nuclear
Example 1:
AB is the hinge support
i at both ends, which is obtained from its cross-sectional area and its moment of inertia
Example 2:
Example 3:
Six: measures to improve the stability of the pressure rod
