兰大《工程力学》13春在线作业3（Lan Da Engineering Mechanics 13 spring online homework 3）.doc

兰大《工程力学》13春在线作业3（Lan Da Engineering Mechanics 13 spring online homework 3） 14 spring 13 autumn big orchid Engineering Mechanics 13 spring online homework 312 Total score: 100 test time: - Radio examination Judgment question Radio examination questions (15 questions, 60 points) 1. the maximum number of independent equilibrium equations for a certain spatial force system is equal to the maximum number of independent equilibrium equations if the force acting lines are passed through a fixed point A. 3 B. 4 C. 5 D. 6 Full marks: 4 The maximum flexural normal stress of the 2. straight section beam occurs at the cross section. A. maximum shear B. has the largest area C. minimum area D. maximum bending moment Full marks: 4 The basic deformation of the 3. bar member does not include (). A. bending torsion deformation B. bending C. shear and extrusion D. twist Full marks: 4 The approximate differential equation of deflection curve of 4. beam is similar The A. cross section does not necessarily keep the plane B. material does not necessarily obey Hookes law The deformation of the C. beam is not necessarily small deformation The two order derivative of D. replaces curvature and ignores the effect of shear Full marks: 4 5. if the sectional figure has a symmetrical axis, the figure is on its axis of symmetry. A. of zero moment of inertia is not zero. B. static moment is not zero, zero moment of inertia C. static moment and moment of inertia are zero D. static moment and moment of inertia are not zero Full marks: 4 6. to study the bending deformation of beams, the main purpose is to solve the beam (s) problem. A. strength B. stiffness C. stability D. support reaction Full marks: 4 7. the number of unknown forces is 4 in statically indeterminate systems. There are 3 static equations listed in the system, and the system is statically indeterminate. A. 1 times B. 3 times C. 4 times D. 12 times Full marks: 4 The 8. end adopts a fixed hinge support, and the other end adopts a movable