This preview shows page 1. Sign up to view the full content.
Unformatted text preview: Assumptions and Modeling Notes
The problem is solved first using the nonlinear spring element (COMBIN39) and then using a spar element (LINK1)
with nonlinear elastic material (nonlinear table).
For the nonlinear spring element (COMBIN39), the nonlinear spring constant is converted to eleven discrete
force-deflection points by F = kδ for δ = 0.0 to 1.0 in steps of 0.1 in.
For the spar element (LINK1) with nonlinear elastic material, the nonlinear spring constant is converted to six
discrete stress-strain points by σ = kδ/A and ε = δ/L for δ = 0.0 to 1.0 in steps of 0.2 in. The elastic modulus EX on
the MP command must be greater than the maximum of σ/ε (= kL/A) and hence is assigned a value of 2kL/A =
12 x 104 psi.
The IC command is used to impose the initial displacement and velocity configuration. The first load step is
defined over a very small time step (.0002 sec) to allow the initial step change in acceleration to be attained. The
integration time step for the second load step is base...
View Full Document
This note was uploaded on 12/09/2010 for the course DEPARTMENT E301 taught by Professor Kulasinghe during the Spring '09 term at University of Peradeniya.
- Spring '09
- The Land