At an axial load of 22 kN, a 45-mm-wide by 10-mm-thick polyimide polymer bar elongates 2.7 mm while the bar width contracts 0.26 mm. The bar is 180 mm long. At the 22-kN load, the stress in the polymer bar is less than its proportional limit. Determine (a) the modulus of elasticity. (b) Poisson's ratio. (c) the change in the bar thickness. Answers: (a) E= (b) v= (c) Athickness= i i i GPa mm

An extruded polymer beam is subjected to a bending moment M.  The length of the beam is L = 580 mm.  The cross-sectional dimensions of the beam are b1 = 36 mm, d1 = 106 mm, b2 = 22 mm, d2 = 22 mm, and a = 7 mm.  For this material, the allowable tensile bending stress is 20 MPa, and the allowable compressive bending stress is 9 MPa.  Determine the largest moment M that can be applied as shown to the beam.

6. Derive the resolved shear stress(RSS) equation for dislocation at an arbitrary plane at angle (e) with horizontal under nominal axial tensile stress(o) and plot the variation of Schmidt factor with

A steel component is subjected to alternate cyclical loading. The steel follows Basquin's law for high cycle fatigue, o, x N = C, (where the stress amplitude is in MPa). Ignore the geometric detail and assume that Marin's modifying factors are all equal to 1. You are given the minimum stress ain = -213 MPa, the maximum stress omax = 213 MPa. The material data are Tensile strength oUTS = 539 MPa, Basquin's constant c, = 875 MPa, Basquin's exponent a = 0.085. a) Calculate the stress ratio R, the stress amplitude o, in MPa and the mean stress am in MPa. The answers are acceptable with a tolerance of 0.01 for R and of 1 MPa the stresses. R: MPa MPа b) Calculate the corresponding life, in 10° cycles, (tolerance of 0.1 106 cycles) N :

Problem 1 An aluminum rod is rigidly attached between a steel rod and a bronze rod as shown. Axial loads are applied at the positions indicated. Aluminum Steel A=800mm2 A=1000mm2 Bronze A=700mm? 4P 2P 500mm 600mm 700mm 1. What is the maximum value of P that will not exceed the axial stress bronze of 105 MPa? 2. What is the maximum value of P that will not exceed the axial stress in aluminum of 90 MPa? 3. If P=10KN, what is the axial force to be carried by the aluminum in KN? 4. If P is 5KN, what is the axial stress of steel?

A steel plate used for polymer forming is to be bent into a circular shape having an inside radius of 10 m. What maximum thickness can be used for the plate if the normal stress is not to exceed 267 MPa? Assume that the modulus of elasticity for the steel is 201 GPa.

Example: the low cycle fatigue of a certain steel is given by life cycle equation-2: (ay/E)=0.005 -0.07 b= -0.08 c= -0.7 a. What is the value of the transition fatigue life, in this case 2 N/when EE - Ep b. What is the total strain amplitude at the transition fatigue life?

An extruded polymer beam is subjected to a bending moment M. The length of the beam is L = 580 mm. The cross-sectional dimensions of the beam are b1 = 33 mm, d1 = 112 mm, b2 = 20 mm, d2 = 20 mm, and a = 6.5 mm. For this material, the allowable tensile bending stress is 15 MPa, and the allowable compressive bending stress is 13 MPa. Determine the largest moment M that can be applied as shown to the beam. b2 a a M d2 A B bị

Narrow bars of aluminum are bonded to the two sides of a thick steel plate as shown. Initially, at T₁ = 70°F, all stresses are zero. Knowing that the temperature will be slowly raised to T₂ and then reduced to T₁, determine (a) the highest temperature T₂ that does not result in residual stresses, (b) the temperature T₂ that will result in a residual stress in the aluminum equal to 58 ksi. Assume aa = 12.8 x 10-6/°F for the aluminum and a = 6.5 × 10-6/°F for the steel. Further assume that the aluminum is elastoplastic with E = 10.9 × 106 psi and ay = 58 ksi. (Hint: Neglect the small stresses in the plate.) Fig. P2.121