The Design And Fabrication Of Initiative Distortion Structure Driven By Shape Memory Alloys

In the field of researching about aviation aircraft structures, the design for aero elasticity of airfoil is one of the most important things. For many years aeroneer is always expected that they can manipulate aircraft not by the control surface, but directly by the deformation of airplane wings to change aerodynamics, so as to obtain the best aero performance. For this reason people put forward the conception of self-adapting wing: this is a kind of flexible wing whose shape and camber can change according to mission needs, driving material is generally SMA.As a kind of functional material, the research on NiTi SMA is mainly concentrated on the field of materials. But when it is used as driving component of structure deforming initiatively, we need synthetically test its performance during the phase transformation, such as mechanics, electricity, calorifics etc. To this problem, in this paper I do a comprehensive testing analysis and summary for NiTi SMA, as follows: DSC for transformation temperature; stress-strain under the condition of constant temperature (σ—ε)T;strain-temperature under the condition of freedom(ε—T);stress-temperature under the condition of constant strain (σ—T )ε.All of these can provide reference and gist for the design , simulation and fabrication of SMA driver.Shape memory alloys have the advantages of great recovery force and stable performance, connected with corrugated sheets by the form of discrete dots. Through electrifying SMA,utilizing its drawing or retractile force, we can achieve the end of controlling structure to deform on its own initiative.By the characteristic of SMA, make corrugated sheets structure driving by SMA and do numerical simulation with finite element software. In the existing and current finite element analytical software, there is no element and material model simulating shape memory effect of SMA .So in the paper according to the particularity of SMA material,adopt the method called as"negative thermal strain", along with the commercial finite element software ANSYS to stimulate and predict the deformation of structure driven by SMA .By the relationship between temperature and recovery force, select temperature as the feedback and...