Gere & Goodno — Applications of Plane Stress: Problem 8.2-6

8.2-6 A rubber ball (see figure) is inflated to a pressure of 65 kPa. At that pressure, the diameter of the ball is 240 mm and the wall thickness is 1.25 mm. The rubber has a modulus of elasticity \(E = 3.7\) MPa and Poisson’s ratio \(\nu = 0.48\). (a) Determine the maximum stress and strain in the ball. (b) If the strain must be limited to 0.425, find the minimum required wall thickness of the ball.