The average stress σm and stress amplitude σa of the alternating stress in the figure are respectively ( ).[img=239x154]17de8405f43ce66.jpg[/img]
A: σm = 40MPa,σa = -120 MPa
B: σm = -40MPa,σa = -40 MPa
C: σm = 0MPa,σa = 120 MPa
D: σm = -40MPa,σa = 80 MPa
A: σm = 40MPa,σa = -120 MPa
B: σm = -40MPa,σa = -40 MPa
C: σm = 0MPa,σa = 120 MPa
D: σm = -40MPa,σa = 80 MPa
D
举一反三
- If the beam is subjected to a bending moment of M = 16 kN.m, the maximum bending stress inthe beam is ( ). [img=758x530]17de83378488e00.jpg[/img] A: 48.6 MPa B: 74.5 MPa C: 59.6 MPa D: 85.4 MPa
- If the beam is subjected to a bending moment of M = 15 kN.m, the maximum bending stress inthe beam is ( ). [img=443x401]1803275dfac22cc.jpg[/img] A: 5.88 MPa B: 3.92 MPa C: 1.96 MPa D: 7.84
- The bending stress developed at corners A is ( ). [img=480x470]1803275e1832bda.jpg[/img] A: 30 MPa (Tension) B: 30 MPa (Compression) C: 42 MPa (Tension) D: 42 MPa (Compression)
- 原油压缩系数单位是()。 A: kg/m B: MPa C: MPa~1 D: MPa•s
- 井筒储集常数的单位是()。 A: m/Pa B: m/MPa C: MPa/m D: m.Pa
内容
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石油压缩系数的单位是() A: (A)kg/m³ B: (B)Mpa C: (C)MPa﹣¹ D: (D)mPa•s
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原油压缩系数单位是()。 A: kg/m<sup>3</sup> B: MPa C: MPa~1 D: MPa•s
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图示工字钢简支梁,弹性模量E =200GPa,在力偶M作用下测得横截面B顶面的纵向应变 e = 0.0003。则梁内最大弯曲正应力是( )。[img=539x221]1803e33303fd6dc.png[/img] A: 180 MPa B: 30 MPa C: 60 MPa D: 120 MPa
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图示单元体,若sa = 50 MPa,sb = 。[img=150x144]18037a30c22bd6d.jpg[/img] A: 150 MPa; B: 100 MPa; C: 50 MPa; D: 0 MPa。
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在以下状态点中,乙烷属于超临界状态的包括()。 A: 40 ℃,5.1 MPa B: 33 ℃,4.9 MPa C: 50 ℃,4.7 MPa D: 25 ℃,5.5 MPa