What type of stress is induced when a constrained machine component is heated____________________?
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Answer: C. compressive stress
Explanation
Heating a constrained machine component causes thermal expansion that is physically prevented by its fixed supports. This restriction induces internal mechanical pressure within the material without any external forces being applied. Because the material tries to expand but cannot, internal compressive stress builds up rapidly. Thermal stress develops whenever a material experiences temperature changes combined with movement constraints. Most engineering metals expand when heated and contract when cooled according to thermal expansion coefficients. Compressive stress pushes material particles closer together across internal planes.
Railroad tracks require expansion joints to prevent severe compressive buckling during hot summer days. Power plant piping systems must be designed with flexibility loops to accommodate thermal expansion stresses. Engineers must account for thermal stresses when fitting tight machine components at elevated temperatures. Option A refers to maximum or minimum normal stresses occurring on specific principal planes. Option B describes tensile stress, which is caused by pulling forces rather than restricted thermal expansion. Option D involves sliding forces parallel to a plane, which are typical of torsional loading.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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