A systematic analytical study has been initiated to investigate static and dynamic control of lifting surfaces through material and electric damping and control. Sensitivity studies to determine significant parameters are in progress to control creep divergence, flutter, control surface effectiveness, and the impact of aerodynamic noise. Sandia National Laboratories, DOE SNL BF-0162 Mechanical joints are recognized to be responsible for much of the uncertainty in the behavior of otherwise linear structures. Two mechanisms that have been identified as both present and important are microslip in the vicinity of connectors, such as bolts, and slap between adjacent parts of a structure, particularly at high frequencies. Analysis and experiments have been used to characterize the behavior of two beams connected by a bolted joint.
Work continues on the development of predictive models.
In this project, various strategies for extending the life of highway bridges will be examined, including passive, semiactive, and active control strategies for limiting bridge response to heavily loaded vehicles. Advanced composite laminates are being used in flight vehicles to improve performance by substantial structural weight savings. Present numerical analysis requires computers with large storage and takes long real time to complete the calculations. The method under development uses Laplace transforms and thereby requires computer real time use comparable to elastic anisotropic analyses. Results of various loading conditions compare extremely well with exact analytical solutions.