课程名称︰材料力学
课程性质︰必修
课程教师︰施文彬
开课学院：工学院
开课系所︰机械工程学系
考试日期（年月日）︰104/3/31
考试时限（分钟）：110分钟
试题 :
Prelim 1, Mechanics of Materials, Spring 2015
10:20 am-12:10 noon, Mar. 31
Please prmide details of your calculation. Good luck!
1. (20%) A rigid bar is supported by a pin at A and two linearly elastic wires
at B and C, as shown in the figure. The area of the wire at B is 80 mm^2 and
for the one at C is 100 mm^2. Determine the reactions at A, B, and C caused
by the applied force P= 6 kN.
http://imgur.com/pgwsoEq
2. (20%) A rod is fixed at A and loaded with an axial force P, as shown in the
figure. The material is elastic-perfectly plastic, with E = 200 GPa and a
yield stress of 20 MPa. Prior to loading, a gap of 3 mm exists between the
end of the rod and fixed support C. The cross section from A to B is 200 mm^2
and that from B to C is 100 mm^2.
(a) What is the maximum load P than can exert on the rod?
(b) Following (a), the axial force increases from zero to its maximum load
for the rod, and is then released, What will be the residual displacement
of point B upon release of the applied force?
http://imgur.com/W3wOZUF
3. (20%) A 1.5-m-long hollow steel shaft of 38-mm outer diameter d_1 is to be
made of a steel forwhich τ_all = 65 MPa and G = 77.2 GPa. Knowing that the
angle of twist must not exceed 4 degree when the shaft is subjected to a
torque of 600 N-m, determine the largest inner diameter d_2 that can be
specified in the design.
http://imgur.com/3a2as8e
E
4. (20%) For Isotropic and linearly elastic material, derive that G =