$14\mathrm{.}2.$ The symmetrical rod structure is subjected to load $P$ as shown in Fig. P$14\mathrm{.}2.$ The cross sectional area of the vertical

member is $A,$ and for rest members are $kA,$ where $k$ is any number. Yielding stress for all members is ${}_y.$ Perform the elastic

analysis and calculate $P_{\text{a}\text{l}\text{l}\text{o}\text{w}\text{.}}.$ Calculate the limit load and determine ratio $\frac{P_{lim}}{P_{\text{a}\text{l}\text{l}\text{o}\text{w}}}.$ Use the static method.

Ans. $P_{\underset{?}{lim}}={}_{y}A(1+2$kcos$).$

Fig. P$14\mathrm{.}2$