May 17, 2011

MSC Nastran is Essential to Reducing Weight and Cost of Composite Laminates

SANTA ANA, CA – MSC Software Corporation today announced that a new 2-ply angle composite laminate structure by Stanford University is currently being engineered to reduce the weight and cost of composite laminates with the help of simulations done with MSC Nastran.

The 2-angle building block is being engineered at the Stanford University with the goal of increasing strength and durability by suppressing matrix cracking and offsetting deformation from shear coupling associated with anisotropic layer. Using the current unbalanced [0/25] layer, which offers unexpected values with laminates from 4 fixed angles of unidirectional layers, is much more difficult to homogenize due to the higher number of ply angles.

The 4-angle balanced laminate has been the choice of designers for years because of its metal-like behavior. Bi-angle laminates can have ply stresses engineered to work synergistically. A [0/25] beam has 39% less deflection and more than 30% higher first natural frequency than 4-angle quasi-isotropic laminates. Having 65% less density and 15% less thickness, a [0/25] beam is 55% of the weight of aluminum for the same deflection. With an anisotropic panel subjected to combined normal and shear stresses, the deflection or angle of twist can be manipulated including setting them to zero through simulations done with MSC Nastran by Dr. Melih Papila.

"Through simulations using MSC Nastran, we were able to implement our new approach to design composite structures. Instead of ply-by-ply modeling of a composite laminate, we tried using the smeared properties. We performed analysis and optimization by using a homogenized anisotropic plate instead of the traditional ply-by-ply model. We discovered that as we increased the number of plies in the Finite Element Method (FEM) model, we were able to proportionally save time and effort," said Dr. Melih Papila, Stanford University. "Since we envisioned that laminates will have at least 32 plies, we estimate that the use of simulation tools in MSC Nastran will allow us to increase our work rate by about 32 times."

This new building block of [0/25] for laminated structures is ready for application with unmatched quality and value. Simultaneous weight and cost reduction can finally be realized.

Professor Emeritus Stephen W. Tsai reiterated the importance of MSC Nastran by stating, "Sophisticated simulation features in MSC Nastran will not only help design the best structure, but will more than pay for itself over time, and ensure safety."

"The use of composites is growing at a rapid rate," said Ken Welch, VP of Product Management at MSC Software. "MSC is pleased to see Stanford's reliance on MSC Nastran, and will continue supporting research and development initiatives aimed at improving the modeling and simulation of composite materials so product manufacturers can apply new and better design and development methods."