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Consider a three elastic bar system (statically indeterminate) with external for

ID: 1862056 • Letter: C

Question

Consider a three elastic bar system (statically indeterminate) with external forces. Both the length and the flexibility of each bar are shown in Figure 4. There is a temperature rise, say dT (Co), and the coefficient of thermal expansion is , and the thermal strain can be calculated by the formula T = T. Find the reaction forces R1, R2.

Consider a three elastic bar system (statically indeterminate) with external forces. Both the length and the flexibility of each bar are shown in Figure 4. There is a temperature rise, say dT (Co), and the coefficient of thermal expansion is , and the thermal strain can be calculated by the formula T = T. Find the reaction forces R1, R2.

Explanation / Answer

let there are no reaction forces then it expands by length 3L*(C)dT

but due to the reaction forces the legth does not changes by creating the stress

Y*(3LCdT)/3L =Y*(CdT)

R1 =R2 as both are external forces and should cancel out as the body is in equilibrium

stress =2R1/ (pi*r^2) = Y*cdT =>R1 =R2 =YCdT*pi*r^2