Sma Hybrid Composites For Dynamic Response Abatement Applications：（减轻Sma混合复合材料动态响应的应用程序）.pdfVIP

SMA HYBRID COMPOSITES FOR DYNAMIC RESPONSE ABATEMENT APPLICATIONS Travis L. Turner Structural Acoustics Branch, MS 463 NASA Langley Research Center Hampton, VA 23681{2199 ABSTRACT A recently developed constitutive model and a finite element formulation for pre- dicting the thermomechanical response of SMA hybrid composite (SMAHC) structures is briefly described. Attention is focused on constrained recovery behavior in this study, but the constitutive formulation is also capable of modeling restrained or free recovery. Numerical results are shown for glass/epoxy panel specimens with embedded Nitinol actuators subjected to thermal and acoustic loads. Control of thermal buckling, random response, sonic fatigue, and transmission loss are demonstrated and compared to conven- tional approaches including addition of conventional composite layers and a constrained layer damping treatment. Embedded SMA actuators are shown to be significantly more effective in dynamic response abatement applications than the conventional approaches and are attractive for combination with other passive and/or active approaches. INTRODUCTION Excitation levels for many aerospace vehicle structures are high due to engine noise and turbulent boundary layer fluctuating pressures. The ever-increasing need for weight-efficient structures leads to significant sonic fatigue and interior noise issues. Conventional aerospace structures typically employ passive treatments such as structural stiffening, constrained layer damping, and acoustic absorption materials to reduce the struc