training agenda

• Introduction to FEA using I-DEAS MasterFEM
• Introduction to Nastran
• Dynamic Analysis using MasterFEM and Nastran
• Nonlinear Analysis using Nastran and I-DEAS MasterFEM
• Practical Finite Element Analysis Techniques using Nastran and MasterFEM
• NAS106 - Nastran Superelement Analysis
• Miscellaneous MasterFEM: Optimization and Durability

NAS106 - Nastran Superelement Analysis

One thing that has been consistently demonstrated in finite element analysis is that demand will always exceed existing capabilities. In the early days of computers, when engineers were solving small problems by hand, computers were able to handle problems as large as 11 by 11. Once engineers discovered this ability, the size of engineering problems quickly grew to exceed the capacity of the existing systems. This process has repeated itself time and time again, until modern supercomputers are capable of solving problems involving more than 1,000,000 equations with 1,000,000 unknowns, which is still not enough to satisfy the needs of some engineers. This limit on hardware, combined with budget limitations (large runs are expensive), results in limitations on the ability of engineers to solve large, complicated problems.

A solution to these limitations (both hardware and budget) is the use of superelements in Nastran. Using superelements, one can check segments of the model independently and use the reduced matrices from the check runs in the final full model analysis. Superelements allow different groups to work on different parts of the model. In addition, superelements allow the use of "Global-Local" methods to obtain detailed results by applying results from the full model to refined local models. The automatic restart feature in Nastran makes using super-elements even more efficient. Upon a restart, only the operations necessary to get the right answer are performed. This seminar describes how to perform static and dynamic analysis using superelement techniques. The methodology used in superelement partitioning and its implementation is covered in detail. Special attention is paid to restarts in superelement analysis and applying superelements to dynamic analysis, including component modal synthesis.

Course Content

• Introduction, theory, and overview
• Superelement partitioning and terminology
• Superelement case control
• Loads and boundary conditions
• Output formats
• Plotting
• Multilevel analysis
• Manual and automatic restarts in static analysis
• Resource estimation
• Database management and terminology
  • External superelements
  • Upstream/downstream databases
• Secondary (image and external) superelements
• Dynamic analysis with superelements
• Normal modes analysis
• Reduction techniques for dynamics
• Guyan reduction
  • Generalized dynamic reduction
  • Component modal synthesis
• Transient and Frequency Response Analysis
• Restarts in dynamic analysis

Prerequisites

• Introduction to Nastran
• Basic Dynamic analysis using Nastran

Time	Structure
3 days	50% lecture 50% ongoing problems