93年 - 93 淡江大學轉學考工程數學#55969

科目：研究所、轉學考(插大)◆工程數學 | 年份：93年 | 選擇題數：0 | 申論題數：4

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所屬科目：研究所、轉學考(插大)◆工程數學

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【已刪除】1 (30%) The low-bed trailer (拖車）shown is designed so that the rear end of the bed can be lowered to ground level in order to facilitate the loading of wrecked vehicles (使易於放下廢車)A 1500 kg vehicle has been hauled (拖運）to the position shown by a winch (絞車)；the trailer is then returned to a traveling position where a = 0 and both AB and BE arc horizontal. Considering the weight of the disabled automobile (廢車)， determine the force which must be exerted by the hydraulic cylinder of CD to maintain a position with a = 0.

2. (35%) A centrifugal clutch (離心式離合器）shown has a constant angular velocity of 3000 rpm. Thin curved members AB and CD are connected by pins at A and C to the arm AC which rotates about a fixed point O. Each of the members AB and CD has a mass of 5 g and a radius of 10 inch. As the clutch rotates counterclockwise, two knobs located 30。slide on the inside of a fixed cylindrical surface of radius 11 mm with the coefficient of kinetic Ihction is 0.35. Determine the couple M which must be applied to arm AC. Hint： The distance from the centroid (質量中心）of curved members AB (or CD) to the fixed point O is 7.379 mm.

(a) Determine the principal stresses and show a sketch of the element oriented with principal stresses acting on it

(b) Determine the maximum stresses and show them on a sketch of a properly oriented element.