中国石油大学工程力学期末考试学习笔记.docVIP

中国石油大学（北京）2010—-2011学年第1学期 《 Engineering Mechanics》期末考试试卷/B Class: Name： Registration No.： Score： No. I II III IV V VI VII Total Score Date: Jan 7, 2011 (25points) Give the answer for the following questions. (3 points) For two slender columns with same length, same support condition and made of same material but different cross sections as shown in Fig.1.1, please compare their critical stresses. (3 points) The stress state of a point in a body is shown as Fig.1.2., the equivalent stress 。 (3 point) The square thin plate with loads is shown as Fig. 1.3. If the maximum static friction coefficient between the plate and ground is 0.5, the maximum value of force P is which keeps the plate in rest. ；B． ；C．；D． (3 Points) The columns with their impact loads are shown as Fig. 1.4. The columns are made of same steel. The upper black part of column C is made of rubber. has the maximum dynamic stress. (3 Points) A cantilever beam with loads is shown in Fig.1.5. Its deflection expression in is right. (2 points) Mechanics of Materials deals with the abilities of solid bodies which including 、Rigidity、 . (3 points) In general, the condition of equilibrium has independent equations for a non-coplanar force system and independent equations for a coplanar force system. The condition of equilibrium has independent equations for a non-coplanar parallel force system. (2 points) The endurance limit of specimen which has stress concentration is than the polished specimen that has no stress concentration. The endurance limit of polished small specimen is than the large polished specimen. (3 point) During reduction of a coplanar force system, the vector sum of the forces is taken as its and the vector sum of moments of forces about new action point of forces is known as its . The value of is related to