Exams › GATE › Technical
Consider two concentric circular cylinders of different materials M and N in contact with each other at r = b, as shown below. The interface at r = b is frictionless. The composite cylinder system is subjected to internal pressure P. Let (u_r^M, u_θ^M) and (σ_rr^M, σ_θθ^M) denote the radial and tangential displacement and stress components, respectively, in material M. Similarly, (u_r^N, u_θ^N) and (σ_rr^N, σ_θθ^N) denote the radial and tangential displacement and stress components, respectively, in material N. The boundary conditions that need to be satisfied at the frictionless interface between the two cylinders are:
- u_r^M = u_r^N and σ_rr^M = σ_rr^N only
- u_r^M = u_r^N and σ_rr^M = σ_rr^N and u_θ^M = u_θ^N and σ_θθ^M = σ_θθ^N
- u_θ^M = u_θ^N and σ_θθ^M = σ_θθ^N only
- σ_rr^M = σ_rr^N and σ_θθ^M = σ_θθ^N only
Correct answer: u_r^M = u_r^N and σ_rr^M = σ_rr^N only
Solution
At the frictionless interface between the two materials, the radial displacements must be equal to ensure continuity, and the radial stresses must also be equal to maintain equilibrium. The tangential components do not need to match because there is no friction to enforce that condition.
Related GATE Technical questions
⚔️ Practice GATE Technical free + battle 1v1 →