Question

Problem 1 Three one-meter-long bars with cross-section area A1cm2 support a rigid plate of weight I. For steel, E, - 200 GPa and S, 400 MPa. Determine the maximum weight the bars can support for three cases: Im (i) all three bars are exactly Im long (ii) the outer bars are exactly 1m long but the middle bar is 0.999m (iii the outer bars are exactly Im long but the middle bar is 1.001m

Answer 1

thre e all the 小 Samele nath Case-I:-When la rs are t Pand P are forces ho be. carried thy 3 mes pe chvely sy m m ehicay As the arrangement imau the rhre e. bars γe manns same . 3 P2 L P, L P, L A E A E qa alim 0 wegep From the ab ove As al, the bar s cames equ al farces hey wi认 yielded al-the..sa me time. A3 t ラ 40 Krv

Ans 0)s. Case When midddle baT 0:99m Elong ation im all the bars uill be same R2L2 P2 L3 A E A E O 99 P t.e 2 Bar 2 uwiu yield is CssvdA riom 2. 0940 Ans.

Case 3 Whem middle barisI oof m. 3 A E A E A E 2 2. As ou har bars carries mnaimwm terce_ ., the 13 110 KN → P2 39.96 kN.