Page 45 - Mechanics of Microelectromechanical Systems
P. 45
32 Chapter 1
The torsion equilibrium equation is:
By applying the boundary conditions:
the angular deformation can be written as:
Similar to the case of axial loading, the torsion moment of Eq. (1.111) is
determined as:
where the torsion stiffness is:
The torsion moment of inertia of Eq. (1.117) can be calculated according
to two different models, depending on the relationship between the thickness
t and the width w. For very thin members (t << w), Boresi, Schmidt and
Sidebottom [1] suggest:
whereas for members where t < w, simply, the moment of inertia can be
approximated to:
