课程名称︰机械设计原理 课程性质︰系订必修 课程教师︰尤春风 开课学院：工学院 开课系所︰机械系 考试日期（年月日）︰2009/11/12(四) 考试时限（分钟）：14:20~17:40 (closebook+openbook) closebook部分写完交答案卷 才可领openbook部分 是否需发放奖励金：是 （如未明确表示，则不予发放） 试题 : Close book部分: 1.(10%，每一子题请用文字说明之，每一子题字数请勿少於100字) (a) Please give the detail descriptions of the design processes and also indicate the main requirements and goals of each stage. (b) What are the decomposition approach and combinaiton approach on the design processes? (c) What are the top-down and bottom-up approach on the design processes? 2.(8%，每一子题请用文字说明之，每一子题字数请勿少於50字) Please select one suitable material for the following components, and specify the heat treatment process, if necessary. (a) Hood(引擎盖钣) of the automobile bodies. (b) Gear and pinion which is used to support the heavy loads. 3.(8%，每一子题请用文字说明之，每一子题字数请勿少於50字) (a) Please give two methods of heat treatment for the low carbon steel. (b) Please give two methods of heat treatment for the medium carbon steel. 4.(10%) (a) Please state the distortion energy theory. (b) Please use graphical representation to describe the distortion energy theory if a biaxial stress state (σz=0) is used as an example. (c) When a pure shear of the biaxial stress state is presented, how to find the yielding strength in shear in term of the distortion energy theory. 5.(8%，(a)(b)请用文字说明之，(c)请用文字与图说明之，每一子题字数请勿少於50字) (a) What are redidual stresses? (b) What are the causes of residual stresses? (c) What are the shot peening processes? 6.(8%，每一子题请用文字说明之，每一子题字数请勿少於50字) (a) At what condition, stress-concentration factor does not necessary to be considered for the ductile material? (b) At what condition, stress-concentration factor should be considered for the ductile material? 7.(8%，每一子题请用文字与图说明之) (a) What is the Goodman line? (b) Explain modified Goodman diagram for torsional shear stress. Open book部分: 8. The rod shown in Fig.1 is made of AISI 1040 steel (ultimate strength 500 N/mm^2 , yield strength 400N/mm^2) and has two 90° bends. Use the following criteria to determine the minimum rod diameter for a safety factor of 2.0 at the most critical sections. (a) Maximum shear stress theory (b) Distortion energy theory. 　　　　　　　　　　　300mm 　　　　　▄▃▂▁ 　　　　　▄▃▂▁█▇▆▅▄▃▂▁ 　　　　　 ▇▆▅▄▃▂█◣ 　　　　　 ◢ ◤ 　　　　　 ◢ ◤ 　　　　　 ◢ ◤ 　　　　　 ◢ ◤ 　　　　　 ◢ ◤ 750mm 　　　　　 ◢ ◤ 　　　　　 ◢ ◤ 　　　　　 ◢ ◤ 　　　　 　 　　　　　 50mm 　　　　　 z ▄▄──→100N ↑ ／∣ ↙ →y ↙ ↓ x 1500N 800N 9. A straight,circular rotating simply supported beam with a 1000 mm length has an axial load of 30,000 N applied at end and a ratial load of 800 N applied at middle span of the beam. The beam is cold-drawn and the material is AISI 1040 steel (ultimate strength 500 N/mm^2, yield strength 400 N/mm^2). Find the minimum diameter of the safety factor 2.0 for infinite life by using the following criteria: (a) Goodman line (b) Soderberg line. Please note: All factor for calculating the actual endurance limit can be set as 1.0. -- 那个图....我尽力了~"~ 请把它想成是一个三度空间的rod 沿+y方向300mm,转向+x方向750mm,再转向-z方向50mm 然後在最尾端受到xyz三个不同方向的力 这样 给大家参考看看罗~ --

※ 发信站: 批踢踢实业坊(ptt.cc) ◆ From: 140.112.252.156 ※ 编辑: jw771216 来自: 140.112.252.156 (11/16 20:50)