In this chapter, performing linear static structural analyses in Simulation will be covered:
a.Geometry and Elements
b.Assemblies and Contact Types
c.Analysis Settings
d.Environment, including Loads and Supports
e.Solving Models
f.Results and Postprocessing
The capabilities described in this section are generally applicable to ANSYS DesignSpace Entra licenses and above.
-Some options discussed in this chapter may require more advanced licenses, but these are noted accordingly.
Basics of Linear Static Analysis
For a linear static structural analysis, the displacements {x} are solved for in the matrix equation below:
Assumptions:
-[K] is constant
Linear elastic material behavior is assumed
Small deflection theory is used
Some nonlinear boundary conditions may be included
-{F} is statically applied
No time-varying forces are considered
No inertial effects (mass, damping) are included
It is important to remember these assumptions related to linear static analysis. Nonlinear static and dynamic analyses are covered in later chapters.
A. Geometry
-In structural analyses, all types of bodies supported by Simulation may be used.
-For surface bodies, thickness must be supplied in the “Details” view of the “Geometry” branch.
-The cross-section and orientation of line bodies are defined within DesignModeler and are imported into Simulation automatically.
Point Mass
A Point Mass can be added to a model (Geometry branch) to simulate parts of the structure not explicitly modeled:
-A point mass is associated with surface(s) only.
-The location can be defined by either:
.(x, y, z) coordinates in any user-defined Coordinate System.
.Selecting vertices/edges/surfaces to define location.
-Point mass is affected by “Acceleration,” “Standard Earth Gravity,” and “Rotational Velocity”. No other loads affect a point mass.
-The mass is ‘connected’ to selected surfaces assuming no stiffness between them.
-No rotational inertial terms are present.
Material Properties
Young’s Modulus and Poisson’s Ratio are required for linear static structural analyses:
-Material input is handled in the “Engineering Data” application.
-Mass density is required if any inertial loads are present.
-Thermal expansion coefficient is required if a uniform temperature load is applied.
-Thermal conductivity is NOT required for uniform temperature conditions.
-Stress Limits are needed if a Stress Tool result is present.
-Fatigue Properties are needed if Fatigue Tool result is present.
.Requires Fatigue Module add-on license.
B. Assemblies–Solid Body Contact
When importing assemblies of solid parts, contact regions are automatically created between the solid bodies.
-Contact allows non-matching meshes at boundaries between solid parts
-Tolerance controls under “Contact” branch allows the user to specify distance of auto contact detection via slider bar
In Simulation, the concept of contact and target surfaces are used for each contact region:
-One side of a contact region is referred to as a contact surface, the other side is referred to as a target surface.
-The contact surfaces are restricted from penetrating through the target surface.
.When one side is designated the contact and the other side the target, this is called asymmetric contact.
.If both sides are made to be contact & target this is called symmetric contact.
.By default, Simulation uses symmetric contact for solid assemblies.
.For ANSYS Professional licenses and above, the user may change to asymmetric contact, as desired.
Nonlinear contact types allow an “interface treatment” option:
-“Add Offset”: input zero or non-zero value for initial adjustment
-“Adjusted to Touch”: ANSYS closes any gap to a just touching position (ANSYS Professional and above)
http://www.cadfamily.com/html/Article/Static%20Structural%20Analysis%20Part-A_661_1.htm
http://www.cadfamily.com/html/Article/Static%20Structural%20Analysis%20Part-A_661_2.htm
http://www.cadfamily.com/html/Article/Static%20Structural%20Analysis%20Part-A_661_3.htm
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