Question 2.2: A more complex polynomial for the stress function is Φ= Ax^3...

A more complex polynomial for the stress function is

 

\phi=\frac{A x^{3}}{6}+\frac{B x^{2} y}{2}+\frac{C x y^{2}}{2}+\frac{D y^{3}}{6}
The Blue Check Mark means that this solution has been answered and checked by an expert. This guarantees that the final answer is accurate.
Learn more on how we answer questions.

As before,

\frac{\partial^{4} \phi}{\partial x^{4}}=\frac{\partial^{4} \phi}{\partial x^{2} \partial y^{2}}=\frac{\partial^{4} \phi}{\partial y^{4}}=0

 

so that the compatibility equation (2.9) is identically satisfied. The stresses are given by

 

\frac{\partial^{4} \phi}{\partial x^{4}}+2 \frac{\partial^{4} \phi}{\partial x^{2} \partial y^{2}}+\frac{\partial^{4} \phi}{\partial y^{4}}=0  (2.9)

 

\sigma_{x}=\frac{\partial^{2} \phi}{\partial y^{2}}=C x+D y

 

\sigma_{y}=\frac{\partial^{2} \phi}{\partial x^{2}}=A x+B y

 

\tau_{x y}=-\frac{\partial^{2} \phi}{\partial x \partial y}=-B x-C y

 

We may choose any number of values of the coefficients A, B, C, and D to produce a variety of loading conditions on a rectangular plate. For example, if we assume A = B = C = 0, then \sigma_{x}=D y, \sigma_{y}=0, and \tau_{x y}=0, so that, for axes referred to an origin at the mid-point of a vertical side of the plate, we obtain the state of pure bending shown in Fig. 2.2(a). Alternatively, Fig. 2.2(b) shows the loading conditions corresponding to A = C = D = 0 in which \sigma_{x}=0, \sigma_{y}=B y, \text { and } \tau_{x y}=-B x.

2

Related Answered Questions