content_image/362811.jpg content_image/362812.jpg content_image/362813.jpg
where p is the longitudinal load and q is the transverse load. Via the Hamilton’s principle, we have the equations of motion 

<img src='content_image/362811.jpg'>

with the boundary conditions presented for the brevity sake in the form of partial derivatives of the electric enthalpy function as: at x = 0 

at x = l 

<img src='content_image/362812.jpg'>

<img src='content_image/362813.jpg'>

