Pipe

The pipe section is circular and is characterized by its outer radius and its thickness (in that order). There are 8 integration points equally distributed along the circumference. In local coordinates, the radius at which the integration points are located is \sqrt{(\xi^2+1)/2}, where \xi=r/R, r being the inner radius and R the outer radius. The weight for each integration point is given by \pi*(1-\xi^2)/8 [12].