Physics

Solid Mechanics

510 Questions

Solid mechanics questions evaluate the understanding of stress, strain, and material deformation under various loads. Topics include analyzing beams, cantilevers, and structural steel designs using specific industrial standards. These principles are strictly examined in engineering and civil services preliminary tests.

Stress and strainBeam analysisPrestressed concreteMaterial strengthStructural design

Solid Mechanics Questions

Multiple choice

A rectangular concrete beam of width 120 mm and depth 200 mm is prestressed by pretensioning to a force of 150 kN at an eccentricity of 20 mm. The cross-sectional area of the prestressing steel is 187.5 mm2. Take modulus of elasticity of steel and concrete as 2.1 x105 MPa and 3.0 x104 MPa respectively. The percentage loss of stress in the prestressing steel due to elastic deformation of concrete is

  1. 8.75

  2. 6.125

  3. 4.81

  4. 2.19
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

 

Multiple choice

Which one of following is NOT correct?

  1. Intermediate principal stress is ignored when applying the maximum principal stress theory.

  2. The maximum shear stress theory gives the most accurate results amongst all the failure theories.

  3. As per the maximum strain energy theory, failure occurs when the strain energy per unit volume exceeds a critical value.

  4. As per the maximum distortion energy theory, failure occurs when the distortion energy per unit volume exceeds a critical value.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

(A) In maximum principle stress theory, when the value of maximum principle stress is equal to that of yield point stress as found in a simple tensile test in which we don’t consider intermediate principle stress. (B) Maximum shear stress theory is well justified for ductile matarial because ductile material mostly fails by shear failure. (C) Maximum strain energy over estimate the elastic strength of ductile matarial. (D) As per maximum distortion energy theory, failure occurs when the distortion energy per unit volume exceeds a critical value.

Multiple choice

The stress-strain curve for mild steel is shown in the figure given below. Choose the correct option referring to both figure and table.

  1. P - 1, Q - 2, R - 3, S - 4, T - 5, U - 6

  2. P - 3, Q - 1, R - 4, S - 2, T - 6, U - 5

  3. P - 3, Q - 4, R - 1, S - 5, T - 2, U - 6

  4. P - 4, Q - 1, R - 5, S - 2, T - 3, U - 6
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

(P) Proportionality limit : The highest stress at which stress is directly proportional to strain. (Q) Elastic limit : is the greatest stress at which the material can withstand without any measurable permanent strain after unloading. (R) Yield point/strength is the strength is the stress required to produce a small specific amount of deformation. (T) Ultimate tensile strength : is the maximum load point after it necking begins. (U) Failure point : It is the last point, after it specimen or material got fractured after necking. Stress-strain curve for mild steel.

Multiple choice

A steel cube, with all faces free to deform, has Young’s modulus, E, Poisson’s ratio, v, and coefficient of thermal expansion, $\alpha$. The pressure (hydrostatic stress) developed within the cube, when it is subjected to a uniform increase in temperature, $\triangle T$, is given by

  1. 0
  2. $\frac{\alpha (\triangle T) E}{1-2v}$
  3. $-\frac{\alpha (\triangle T) E}{1-2v}$
  4. $\frac{\alpha (\triangle T) E}{3(1-2v)}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Correct option is (1). There is no pressure development because steel cube is free to deform i.e. there is no restriction.

Multiple choice

A 4-bar mechanism will all revolute pairs has link lengths lf = 20 mm, lin = 40 mm, lco = 50 mm and lout = 60 mm. The suffixes ‘f ’, ‘in’, ‘co’ and ‘out’ denote the fixed link, the input link, the coupler and output link respectively. Which one of the following statements is true about the input and output links?

  1. Both links can execute full circular motion.

  2. Both links cannot execute full circular motion.

  3. Only the output link cannot execute full circular motion.

  4. Only the input link cannot execute full circular motion.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Multiple choice

A thin plate of uniform thickness is subject to pressure as shown in the figure below:

Under the assumption of plane stress, which one of the following is correct?

  1. Normal stress is zero in the z-direction.

  2. Normal stress is tensile in the z-direction.

  3. Normal stress is compressive in the z-direction.

  4. Normal stress varies in the z–direction.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Correct option is (1). From the figure it is clear that normal stress is zero in the z-direction.