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Chapter 5： Torsion Test for Chapter 1~ 3 in book
1、 The method of sections is used to determine the ( ) acting on the surface of the sectioned body. In general, these resultants consist of a ( ), ( ), ( ), and bending moment.
A: resultant loadings, force along x, a force along y axis, torsional moment
B:resultant loadings, normal force, shear force, external couple
C:external resultant loadings, normal force, shear force, torsional moment
D:internal resultant loadings, normal force, shear force, torsional moment
答案: internal resultant loadings, normal force, shear force, torsional moment
2、 ( ) is a measure per unit length of the elongation or contraction of a small line segment in the body, whereas ( ) is a measure of the change in ( ) that occurs between two small line segments that are originally ( ) to one another.
A:Normal strain, shear strain, angle, perpendicular
B:Shear strain, normal strain, angle, perpendicular
C:Normal strain, shear strain, length, perpendicular
D:Shear strain, normal strain, length, perpendicular
答案: Normal strain, shear strain, angle, perpendicular
3、 The rigid beam is supported by a pin at A and wires BD and CE. If the distributed load causes the end C to be displaced 20 mm downward, the normal strain developed in wires DB is ( ) and in wire CE is ( ).
A:0.00266 mm/mm, 0.001 mm/mm
B: 0.00533 mm/mm, 0.005 mm/mm
C:0.00533 mm/mm, 0.01 mm/mm
D:0.00266 mm/mm, 0.005 mm/mm
答案: 0.00533 mm/mm, 0.01 mm/mm
4、 A 100-mm long rod has a diameter of 15 mm. If an axial tensile load of 20 kN is applied to it, the change in its diameter is ( ). E = 70 GPa, υ = 0.35.
A:
B:
C:
D:
答案:
5、 If the elongation of wire BC is 0.3 mm after the force P is applied, the magnitude of P is ( ). The wire is A-36 steel and has a diameter of 3 mm.
A:942 N
B:628 N
C:1256 N
D:314 N
答案: 942 N
6、 A 20-mm-wide block is firmly bonded to rigid plates at its top and bottom. When the force P is applied the block deforms into the shape shown by the dashed line. The block’s material has shear modulus G = 52 GPa. Assume that the material does not yield and use small angle analysis. The magnitude of P is ( ).
A:460 kN
B:130 kN
C:260 kN
D:520 kN
答案: 520 kN
7、 The three suspender bars are made of the same material and have equal cross-sectional areas A. The average normal stress in the bar AB is ( ) if the rigid beam ACE is subjected to the force P.
A:(7P)/(12A)
B:(5P)/(12A)
C:(2P)/(3A)
D:(P)/(2A)
答案: (7P)/(12A)
8、 The solid circular shaft is subjected to an internal torque of T = 8kN·m. The shear stress developed at points A and B are ( ) and ( ), respectively.
A:79.58 MPa, 59.68 MPa
B:49.7 MPa, 37.3 MPa
C:49700 Pa, 37300 Pa
D:79580 Pa, 59680 Pa
答案: 79.58 MPa, 59.68 MPa
9、 The shear stress developed at point A on the surface of the shaft is ( ). The shaft has a radius of 60 mm.
A:11.79 MPa
B:7.42 MPa
C:25.42 MPa
D:30.57 MPa
答案: 11.79 MPa
10、 A bar AB having length L and axial rigidity EA is fixed at end A. At the other end a small gap of dimension s exists between the end of the bar and a rigid surface. A load P acts on the bar at point C, which is two thirds of the length from the fixed end. If the support reactions at A and B produced by the load P are to be equal in magnitude, the size s of the gap is ( ).
A:(PL)/(6EA)
B:(2PL)/(3EA)
C:(PL)/(3EA)
D:(2PL)/(EA)
答案: (PL)/(6EA)
11、 A circular steel rod of diameter d is subjected to a tensile force P = 3.5 kN. The allowable stresses in tension and shear are 118 MPa and 48 MPa, respectively. The minimum permissible diameter dmin of the rod is ( ).
A:3.42 mm
B:6.81 mm
C:4.63 mm
D:5.45 mm
答案: 6.81 mm
12、 When a shaft having a circular cross section is subjected to a torque, the cross section remains plane while radial lines rotate. This causes a ( ) within the material that varies ( ) along any ( ) line.
A:shear strain; linearly; radial
B:normal strain; linearly; radial
C:shear strain; nonlinearly; radial
D: shear strain; nonlinearly; longitudinal
答案: shear strain; linearly; radial
13、 A circular steel tube of length L = 1.0 m is loaded in torsion by torques T. If the inner radius of the tube is r1 = 45 mm and the measured angle of twist between the ends is 0.5°, the shear strain γ1 (in radians) at the inner surface is ( )
A:
B:
C:
D:
答案:
14、 A propeller shaft for a small yacht is made of a solid steel bar 104 mm in diameter. The allowable stress in shear is 48 MPa, and the allowable rate of twist is 2.0° in 3.5 meters. Assuming that the shear modulus of elasticity is G = 80 GPa, the maximum torque Tmax that can be applied to the shaft is ( )
A:9164 N⸱m
B:4582 N⸱m
C:10602 N⸱m
D:8320 N⸱m
答案: 9164 N⸱m
Chapter 7 Transverse Shear Test for Chapters 4 and 5 in book
1、 In the case of a beam, a positive shear force acts ( ) against the material and a negative shear force acts ( ) against the material. Also, a positive bending moment ( ) the upper part of the beam and a negative bending moment ( ) the upper part.
A:clockwise, counterclockwise, compresses, stretches
B:clockwise, counterclockwise, stretches, compresses
C:counterclockwise, clockwise, stretches, compresses
D:counterclockwise, clockwise, compresses, stretches
答案: clockwise, counterclockwise, compresses, stretches
2、 At the point of application of a concentrated load, the bend moment ( ) while the rate of change of the bend moment undergoes ( ). At the point of application of a couple, the shear force ( ) while the bending moment ( ).
A: does not change, an abrupt change, does not change, changes abruptly
B:does not change, no change, changes abruptly, changes abruptly
C:changes abruptly, no change, does not change, changes abruptly
D:does not change, no change, does not change, changes abruptly
答案: does not change, an abrupt change, does not change, changes abruptly
3、 A beam with an overhang at the left-hand end is shown in the figure. Assume the shear force at the cross section x equal to zero, then the value of x is ( ).
A:7a/6
B:5a/6
C:6a/5
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