טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
Ph.D Thesis
Ph.D StudentRevivo Michael
SubjectAnalysis of Soft Composite Structures
DepartmentDepartment of Aerospace Engineering
Supervisor Professor Omri Rand
Full Thesis textFull thesis text - English Version


Abstract

The Aerospace industries, both Civilian or military, tend to incorporate more and more soft composite structures made of advanced and non-classical materials, making use of their specific mechanical properties like coupling elastic effects of composite layered materials for tailored helicopter blades, large elastic range of elastomers for light dampers, or hyper-elastic performance of Shape Memory Alloys in smart actuators of satellites' solar panels. One may classify the phenomena involved in the prediction of the mechanical behavior of such structures into three categories:


  1. Large Elastic Strains
  2. Large Displacements and/or Rotations
  3. Non-linear material laws

Approximated solutions of such structural problems require the use of analytical or numerical tools with expanded computational capabilities. The present research presents an analytical formulation based on the classical elastic theory for slender beams of general anisotropy, which can be the general core of iterative calculus schemes. This formulation has the ability of treating prismatic beams of generic cross-section and made of general anisotropic material. Also, this method extends the theory developed by Lekhnitskii for constant stress distribution, to general loading conditions that include local tip forces and tip moments, distributed surface loads and distributed body loads varying inside the cross section and also along the beam axis. This linear core is then placed in the center of numerous original approximated iterative schemes dealing with each one of the three non-linear phenomena specific to soft composite structures as described earlier. The results, obtained by using a symbolic MAPLE© code, are then discussed qualitatively and compared quantitatively with numerical results obtained with ANSYS© Finite Elements models.