RADIOSSLinear90002文档.ppt

Inertia Relief A few different ways of requesting for an Inertia Relief analysis SUBCASE 6 $ Defines subcase number 6 LOAD = 6 $ references all static load cards with ID = 6 SUPORT1 = 8 $ references all SUPORT1 cards with ID = 8 SUBCASE 6 $ Defines subcase number 6 LOAD = 6 $ references all static load cards with ID = 6 … BEGIN BULK PARAM,INREL,-2 $Defines inertia relief without a suport point SUBCASE 6 $ Defines subcase number 6 LOAD = 6 $ references all static load cards with SID = 6 … BEGIN BULK SUPORT, 10,6, $Grid ID, DOF’s Supported, … Inertia Relief Results of interest usually are : Displacements, Stresses and Strains Chapter 6: Buckling Analysis What is Linear Buckling Analysis? 3-D Model Linear Buckling Analysis Structures are said to buckle when a certain combination of loads causes the structure to continue to deflect without an increase in the magnitude of the load The critical load at which buckling occurs is the product of the critical buckling factor and the applied reference load The buckling factor is an eigenvalue and has no dimension Generally speaking, the lowest buckling load is usually of the most interest to engineers, since a structure will fail prior to reaching any higher buckling loads Linear Buckling Analysis The problem of linear buckling is solved in two stages: A standard linear static analysis is carried out to obtain stresses, which form the geometric stiffness matrix . The buckling loads are then calculated by solving the eigenvalue problem. Requires STATSUB card for a Buckling Analysis: $$Case Control Cards $ $ SUBCASE 1 SPC = 2 LOAD = 3 $ SUBCASE 2 SPC = 2 METHOD = 1 STATSUB = 1 $ BEGIN BULK EIGRL 1 2 MASS FORCE 3 82 01.0 0.0 0.0 -1000.0 SPC 2 1 123 0.0 $ Linear Buckling Analysis Results of interest usually are : von Mises