AE4131 ABAQUS Lecture Part 3 - ia Institute of.ppt

Starting ABAQUS CAE You can start ABAQUS CAE from the start menu or with mand line by typing abaqus cae TIP: You should start ABAQUS CAE via command line from the directory you want your results files to end up. Dynamics ? We have seen how we pute and view the results of static loading on 1D, 2D and 3D models. ? We may also be interested in how a model moves as a function of time or dynamic modeling .? Reason : Stresses and displacements can be greater in a dynamic model than a static model. The Beam Example: Let ’ s look at a 3D beam that has dimensions of 1m length , m height , and m width . Material Properties ? We used standard 2014-T6 aluminum alloy properties which are: – Density: 174 lbm/ft 3 (2800 kg/m 3) – Young ’ s modulus : 10,400,000. psi (72 GPa) – Poison ’ s ratio: The Step Module Under the General procedure type there are two basic types of dynamic analysis; implicit and explicit . – ABAQUS/Standard uses the implicit Hilber-Hughes- Taylor operator for integration of the equations of motion. This offers the use of all elements in ABAQUS but can be slower than Explicit. – ABAQUS/Explicit uses the central-difference operator. In an implicit dynamic analysis the integration operator matrix must be inverted and a set of nonlinear equilibrium equations must be solved at each time increment. ABAQUS Explicit ABAQUS/Explicit offers fewer element types than ABAQUS/Standard . For example, only first-order, displacement method elements (4-node quadrilaterals, 8- node bricks, etc.) and modified second-order elements are used, and each degree of freedom in the model must have mass or rotary inertia associated with it. However, the method provided in ABAQUS/Explicit has some important advantages: 1. The analysis cost rises only linearly with problem size, whereas the cost of solving the nonlinear equations associated with implicit integration rises more rapidly than linearly with problem size. T