A vertical bar consists of three prismatic segments A1, A2, and A3 with cross-sectional areas of 6000 mm2 , 5000 mm2 , and 4000 mm2 , respectively. The bar is made of steel with E 5 200 GPa. Calculate the displacements at points B, D

Respuesta :

Answer and Explanation:

For computing the displacement at point B and D we need to determine the following calculations

[tex]P_Net = P_C + P_E + P_B[/tex]

= 250 + 350 - 50

= 550 N

Now the deflection for bar AB is

[tex]\delta_{AB} = \frac{PL_{AB}}{AE} \\\\ = \frac{550 \times 500}{6,000 \times 200 \times 10^{3}}[/tex]

[tex]= 2.292 \times 10^{-4} mm[/tex]

Now for bar BC it is

[tex]\delta_{BC} = \frac{PL_{BC}}{AE} \\\\ = \frac{(550 + 50) \times 250}{5,000 \times 200 \times 10^{3}} \\\\ = 1.5 \times 10^{-04} mm[/tex]

And for bar CD it is

[tex]\delta_{CD} = \frac{PL_{CD}}{AE} \\\\ = \frac{(550 -250 + 50) \times 250}{5,000 \times 200 \times 10^{3}} \\\\ = 0.875 \times 10^{-4} mm[/tex]

Now the displacement is as follows

For B

2.292 × 10^{-4} mm

For D, it is

[tex]= 2.292 \times 10^{-4} + 1.5 \times 10^{-4} + 0.875 \times 10^{-4} mm \\\\ = 4.667 \times 10^{-4} mm[/tex]

We simply applied the above formulas for determining the  displacements at points B, D and the same is to be considered  

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