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Initial Equilibrium Force

 

Overview

IMG_C_ICON_DOT.gifUse the prestress function to apply the resultant force or stress as initial conditions, depending on the element type. If the initial stress state is given as such, a force corresponding to the initial stress occurs. This initial equilibrium force uses the force created by the initial stress from the prestress function as an external force. If additional external forces do not exist, the initial equilibrium force is in equilibrium with the initial stress, hence the initial state is maintained. Also, use the [Self-Weight Consideration] option to assume the initial stress to be caused by gravity. If this assumption is applied, the load distribution factor considering the self weight of the element is applied when the element is removed from the construction stage.

 

Methodology

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[Element Type]

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The applicable element types are as follows and the input load component is different for each type. The target shape can be selected by directly selecting the element or geometry shape (edge, face, solid), depending on the selected element type. For shapes, the selected shape must have been used for element creation and the input load is applied to all element nodes within the shape.

 

[Components]

Define the load or stress for each axial direction and use a function to simulate the linear increment/decrement of the load size with reference to the global coordinate system (GCS). The load components for different element types are as follows:

  • Nxx : Initial axial force acting on 1D element

  • Mx, My, Mz : Bending force (moment load) with reference to each element coordinate system

  • Sxx, Syy, Szz : Axial stress in each axial direction

  • Sxy, Syz, Szx : Shear stress in each plane direction

The load application direction for the initial stress of Plane/Axis symmetric/Solid elements can be set with reference to the GCS or element coordinate system.

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