Determine the magnitude of P for equilibrium and total elongation of the bar shown in fig. Take E = 210 Gpa. Also calculate minimum stress induced.
Nov 19, 2023To determine the magnitude of P for equilibrium and total elongation of the bar shown in the figure, we can use the following steps: Calculate the cross-sectional area of each section of the bar. A1 = π/4 * 20^2 = 125.66 mm^2 A2 = π/4 * 30^2 = 282.74 mm^2 Calculate the total load on the bar. P = A1 * σ1 + A2 * σ2 where σ1 and σ2 are the stresses in sections 1 and 2, respectively. Calculate the stresses in sections 1 and 2. σ1 = E * ε1 σ2 = E * ε2 where ε1 and ε2 are the strains in sections 1 and 2, respectively. Calculate the strains in sections 1 and 2. ε1 = δl1 / L1 ε2 = δl2 / L2 where δl1 and δl2 are the elongations of sections 1 and 2, respectively, and L1 and L2 are the lengths of sections 1 and 2, respectively. Set the elongations of sections 1 and 2 equal to each other, since the two sections are connected. δl1 = δl2 Substitute the equations for ε1 and ε2 into the equation for δl1 = δl2. δl1 / L1 = δl2 / L2 Solve the equation for δl1 or δl2. δl1 = L1 * δl2 / L2 Substitute the equation for δl1 into the equation for ε1. ε1 = δl1 / L1 = (L1 * δl2 / L2) / L1 = δl2 / L2 Substitute the equation for ε1 into the equation for σ1. σ1 = E * ε1 = E * (δl2 / L2) Substitute the equations for σ1 and σ2 into the equation for P. P = A1 * E * (δl2 / L2) + A2 * E * (δl2 / L2) Factor out the δl2 and E terms. P = δl2 / L2 * (A1 * E + A2 * E) Solve the equation for δl2. δl2 = P / (A1 * E + A2 * E) * L2 Substitute the equation for δl2 into the equation for ε1. ε1 = δl2 / L2 = P / (A1 * E + A2 * E) * L2 / L2 = P / (A1 * E + A2 * E) Substitute the equation for ε1 into the equation for σ1. σ1 = E * ε1 = E * (P / (A1 * E + A2 * E)) Substitute the equations for σ1 and ε1 into the equation for ε2. ε2 = σ1 / E = (P / (A1 * E + A2 * E)) / E = P / (A1 * E + A2 * E) * (1 / E) Substitute the equation for ε2 into the equation for δl2. δl2 = ε2 * L2 = (P / (A1 * E + A2 * E) * (1 / E)) * L2 = P * L2 / (A1 * E + A2 * E) Therefore, the magnitude of P for equilibrium is: P = δl2 * (A1 * E + A2 * E) / L2 And the total elongation of the bar is: δl2 = P * L2 / (A1 * E + A2 * E) Solution: Given: L1 = 500 mm L2 = 1000 mm A1 = 125.66 mm^2 A2 = 282.74 mm^2 E = 200 GPa P = 5
Nov 20, 2023