Ridif bar ABC is supported with a pin at A and an elastic steel rod at C. The elastic rod has a diameter of 25mm and modulus of elasticity E = 200 GPA. The bar is subjected to a uniform load q on span AC and a pointload at B.


Calculate the change in length of the elastic rod.


What is the vertical displacement at point B?

Respuesta :

Answer:

the change in length of the elastic rod is 0.147 mm and the vertical displacement of the point b is 0.1911 mm.

Explanation:

As the complete question is not visible , the complete question along with the diagram is found online and is attached herewith.

Part a

Take moments at point A to calculate the tensile force on the steel

rod at point C

[tex]\sum M_A=0\\T_c*2.5-P(2.5+0.75)-q*2.5*2.5/2=0\\T_c*2.5-10(3.25)-5*3.125=0\\T_c=19.25 kN\\[/tex]

Calculate the change in length of the elastic rod

[tex]\Delta l=\dfrac{T_c*L}{A*E}\\\Delta l=\dfrac{19.25\times 10^3*0.75}{\pi/4\times 0.025^2*200\times 10^9}\\\Delta l=0.000147 m \approx 0.147 mm[/tex]

So the change in length of the elastic rod is 0.147 mm.

As by the relation of the similar angles the vertical displacement of the point B is given as

[tex]\Delta B=\Delta l\dfrac{AC+BC}{AC}[/tex]

Here AC=2.5 m

BC=0.75 m

Δl=0.147 mm so the value is as

[tex]\Delta B=\Delta l\dfrac{AC+BC}{AC}\\\Delta B=0.147 mm\dfrac{2.5+0.75}{2.5}\\\Delta B=0.147 mm\dfrac{3.25}{2.5}\\\Delta B=0.1911 mm[/tex]

So the vertical displacement of the point b is 0.1911 mm.

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