**01. Principles of Statics and the Free-Body Diagrams**

**Test of Chapter 1**

1、The constraint at Point C is

A、Pin support

B、Roller support

C、Built-in support

D、Lever

2、“axiom of two forces in equilibrium” can be applied to deformable body.

3、The constraint at point B is a Pin support.

4、Which bar is a “two-force body” ?

**02. Basic Operations with Force Systems**

**Test of Chapter 2**

1、Consider the coplanar force system shown in the following figure, F1=200N, F2=300N, F3=100N, and F4=250N. The magnitude of the resultant of the four forces is

A、171.3 N

B、71.3 N

C、100 N

D、173.2 N

2、

A、

B、

C、

D、

3、

A、

B、

C、

D、

4、

**03. Reductions and Resultants of Force System**

**Test of Chapter 3**

1、The Principal Moment is related to moment center point O

2、A force at a given point can always be replaced by a force at a different point and a couple-vector that is parallel to the force.

3、The resultant force and the principal vector are the same

**04. Equilibrium of Coplanar Force System**

**Tset of Chapter 4**

1、

A、

B、

C、

D、

2、

A、

B、

C、

D、

3、

**05. Axial tension and compression**

**Test of Chapter 5**

1、Low carbon steel will occur in the yield stage ( )

A、Elasticity

B、Linear elasticity

C、Plasticity

D、Elasticity and plasticity

2、The plane assumption in axial tension and compression is applicable to ( ).

A、Everywhere along the length of the rod

B、Everywhere except the two ends of the rod

C、Everywhere a bit far from the afterburner end of the rod

D、Everywhere along the width of the rod

3、The relationship between internal force and stress is ( ).

A、Internal force is greater than stress

B、Internal force is equal to the algebraic sum of stress

C、Internal force is vector and stress is scalar

D、Stress is the concentration of distributed internal force

4、the factors that affect the ultimate stress are ( ).

A、Load

B、Material properties

C、Section size

D、Working conditions

5、The factors that affect the working stress of members are ()

A、Load

B、Material properties

C、Section size

D、Working conditions

6、the external force causing the axial tension and compression deformation of the rod must be a pair of concentrated forces along the axis of the rod ( ).

7、Only statically indeterminate structures can have assembly stress and temperature stress( ).

8、In axial tension, the ratio of axial stress to strain is always constant( ).

9、After the rod is extended, the transverse direction will be shortened, because there is transverse stress in the rod( ).

10、Internal force refers to the internal force of an object after external force( ).

11、the greater the axial force is, the easier the bar is to be broken, so the axial force can be used to judge the strength of the bar( ).

12、Due to cold work hardening, low carbon steel materials will increase ____ and decrease _____.

13、Connect the elastic modulus of E1 and E2 to two rods of the same shape and size in parallel on the rigid plates at both ends, as shown in the figure. If the deformation of the two rods is equal under the load F, the relationship between E1 and E2 should be _______.

14、The total deformation of the ladder-shaped tie rod shown in the figure is ______.

**06. Torsion**

**Test of Chapter 6**

1、According to the plane assumption of the torsion of a circular shaft, it can be considered that when the circular shaft is twisted, it is on the cross section. ( )

A、The shape and size remain unchanged, and the straight line is still a straight line

B、When the shape and size change, the straight line is still a straight line

C、Shape and size remain unchanged, straight line does not keep straight line

D、Shape and size change, straight line does not keep straight line

2、It is known that the material and cross-sectional area of the two circular shafts shown in figure (a) and figure (b) are equal. If the torsion angle of end face B relative to fixed end a shown in figure (a) is , then the torsion angle of end face B relative to fixed end a shown in figure (b) is ( )

A、

B、2

C、3

D、4

3、The magnitude of shear stress can be equal or different on two mutually perpendicular sections of the element body. ( )

4、The maximum shear stress only appears on the cross section of a torsion shaft. ( )

5、When the circular shaft is twisted, there are both normal stress and shear stress on the cross section. ( )

6、The maximum shear stress occurs at the midpoint of the long side of the rectangle when the bar with rectangular section is twisted. ( )

7、In the same gearbox, the diameter of the high-speed shaft is , and the diameter of the low-speed shaft is . the materials of the two shafts are the same. The relationship between the diameters of the two shafts should be ________

8、If the diameter of solid circular shaft is doubled, the torsional section coefficient increases_______times.

**07. Bending forces**

**Test of Chapter 7**

1、When designing steel beam, the section with neutral axis () should be adopted; when designing cast iron beam, the section with neutral axis () should be adopted.

A、Axis of symmetry

B、Unsymmetrical axis deviating from the tension side

C、Unsymmetrical axis deviating from compression side

D、Symmetric or asymmetric axis

2、when designing cast iron beam, the section with neutral axis () should be adopted.

A、Axis of symmetry

B、Unsymmetrical axis deviating from the tension side

C、Unsymmetrical axis deviating from compression side

D、Symmetric or asymmetric axis

3、When asymmetrical thin-walled cross-section beam bears lateral force, if the beam is required to only be bent in plane without torsion, the condition for the lateral force is ().

A、The acting surface coincides with the main inertia plane of the centroid

B、The acting surface is parallel to the principal inertia plane of the centroid

C、Any plane passing through the center of the bend

D、Pass through the center of bending and parallel to the principal plane of inertia of the centroid

4、When a straight beam with constant cross section is bent and deformed, the largest deflection curve curvature occurs at ().

A、Maximum deflection

B、Maximum turning angle

C、Maximum shear

D、Maximum bending moment

5、It is more advantageous to design the main steel girder of the bridge crane as an overhanging girder with two ends extending outwardly than a simple supported girder. The reason is ()

A、Reduced the maximum bending moment of the beam

B、Reduced the maximum shear value of the beam

C、Reduced the maximum deflection value of the beam

D、Increased the bending stiffness of the beam

6、In order to improve the bending rigidity of the beam, it can be realized by ().

A、Choose high-quality materials

B、Reasonably arrange the beam support to reduce the span length of the beam

C、Reduce the load acting on the beam

D、Choose a reasonable cross-sectional shape

7、When the beam is in pure bending, the cross section remains plane after deformation, and its shape and size remain unchanged. ()

8、When the beam is bending under transverse force, the maximum shear stress on the cross section does not necessarily occur on the neutral axis of the section. ()

9、The cross section of the beam is square. In order to increase the bending section coefficient and improve the strength of the beam, the neutral axis should pass through the diagonal of the square. ()

10、The position of the bending center of the bar is only related to the geometry and size of the section, but not to the load. ()

11、The deflection of the cross section with zero bending moment in the beam is also zero. ()

12、The corner of the cross section at the maximum deflection of the beam must be equal to zero. ()

13、Draw the approximate shape of the deflection curve, not only according to the bending moment diagram of the beam, but also considering the supporting conditions of the beam .()

14、The cross-sectional area of the beam is A. The bending section coefficient is W, and the index to measure the rationality and economy of the section is .

**08. Stress in Bending**

**Test of Chapter 8**

1、When the beam is bent in plane, its cross section rotates around ( ).

A、Axis of beam

B、Section symmetry axis

C、neutral axis

D、Section centroid

2、For cast iron beam as shown in the figure, It is reasonable to use the section shape of ( ) according to normal stress strength.

A、

B、

C、

D、

3、Two cast iron beams are shown in the figure, which are made of the same material and are subjected to the same load. When the load increases, the failure is ( ).

A、Two beams will be in failure simultaneously

B、Beam（a）will be in failure first

C、Beam（b）will be in failure first

D、Unable to determine

4、When the beam is in pure bending, the cross section remains plane after deformation, and the shape and size remain unchanged. （）

5、When the beam is bending under transverse force, the maximum shear stress on the cross section does not necessarily occur on the neutral axis of the section. ( )

6、The position of the bending center of the bar is only related to the shape and size of the cross section, but not to the load. ( )

**09. Deformations of beams due to bending**

**Test of Chapter 9**

1、When a straight beam with constant cross section is bent, the maximum curvature of the deflection curve occurs where ( )

A、the deflection is maximum

B、the angle of rotation is maximum

C、the shearing force is maximum

D、the moment is maximum

2、When applying the superposition principle to calculate the deflection and rotation angle of the beam cross section, the condition to be satisfied is ( ).

A、The beam must be of equal section

B、The beam must be statically determinate

C、The deformation must be small

D、The bending of beam must be plane bending

3、The deflection of the cross section with zero bending moment in the beam is also zero. ( )

4、The rotation angle of the cross section at the maximum deflection of the beam must be equal to zero. ( )

5、The basic statically determinate system of statically indeterminate beams must be statically determinate and geometrically invariant. ( )

6、For cantilever beam with circular section as shown in the figure, which is subjected to a concentrated force at the free end. When the diameter of the beam is reduced by one time and other conditions remain unchanged, the maximum bending normal stress is ( ) times of the original.

7、The figure shows a statically indeterminate beam subjected to a uniformly distributed load. When the length of beam is doubled and other conditions remain unchanged, the deflection of the midpoint of the beam is ( ) times of the original.

**10. Analysis of Stress and Strength Theory**

**Test of Chapter 10**

1、In ball bearing, the stress state at the contact point between ball and outer circle is （ ） stress state.

A、uniaxial

B、plane

C、three dimensional

D、pure shear

2、For the definition of element， the correct answer is （ ）

A、The three-dimensional dimension of the element must be small

B、The element is a parallelepiped

C、The element must be a cube

D、The element must have a pair of cross sections

3、The pure shear element belongs to unidirectional stress state.（ ）

4、The element at any point of pure bending beam belongs to two-dimensional stress state. ( )

5、If the normal stress along a certain direction at a point on the member is zero, the linear strain in that direction is also zero. ( )

6、The strength condition under complex stress state can not be established directly by experiment.

7、Strength theory can only be applied to complex stress states.（ ）

8、In the plane stress state, the sum of the normal stresses in the planes perpendicular to each other is equal to ( ).

**11. Combined Loadings and Deformations**

**Test of Chapter 11**

1、For a member with combined with tension (compression) and bending deformation, the stress state of each point in the member is uniaxial if the shear force on the cross section is ignored.( )

2、When each point of a member is in a complex stress state, we can say that the member is subjected to combined deformations. ( )

3、The critical points of tension (compression) and torsion, bending and torsion are in the state of ( ) stress.

4、The basic method of calculating combined deformation is ( ).

5、The combination of two or more ( ) is called combination deformation.

**12. Stability of Compressed Columns**

**Test of Chapter 12**

1、As shown in the figure, the length coefficient of a compression bar with one end fixed and one end elastically supported is（ ）.

A、less than 0.7

B、larger than 2

C、between 0.7 and 2

D、uncertain

2、In the stability calculation, the critical force of a compressed column is Fcr by using Euler formula. If in fact the compressed column has intermediate flexibility bar, which is the correct statement in the following.（）

A、It does not affect the critical force of the compressed column

B、The actual critical force is larger than Fcr and the column is safe

C、The actual critical force is less than Fcr and the column is unsafe

D、The actual critical force is larger than Fcr and the column is unsafe

3、When the cross-sectional area and other conditions are the same, the compressed column with the cross-sectional shape shown in the figure ( ) has the best stability.

A、

B、

C、

D、

4、If the same safety factor is taken for both strength calculation and stability calculation, which is correct in the following statements.( )

A、The compressed column satisfying the strength condition must satisfy the stability condition

B、The compressed column satisfying the stability condition must satisfy the strength condition

C、The compressed column satisfying the stability condition does not necessarily satisfy the strength condition

D、The compressed column which does not satisfy the stability condition must not satisfy the stability condition

5、The critical stress of a compressed column is proportional to the elastic modulus of the material.( )

6、The critical force and stress of a compressed column is related to the applied load.( )

7、The critical force of two compressed columns with the same material, length, cross-sectional area must be the same. ( )

8、The main cause of the instability is the critical force or critical stress rather than the external disturbance force. ( )

9、For two members which are in failure due to instability or lack of strength respectively, the difference between two member is that the former member is unstable and the latter is stable. ( )