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Temperature and Heat
How Temperature Changes Create Stress
Description
Thermal stress is the stress that builds up when an object changes temperature but cannot expand or contract freely. If the object would expand without restraint, the stress is compressive. If it would contract, the stress is tensile.
This stress from heating or cooling can become large enough to...
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Transcript
当物体经历温度变化时会产生应力,这种应力称为热应力,甚至可能导致物体发生永久性变形。
例如,在铁路轨道上,两根杆件的接头之间会特意留出空隙,以防止杆件发生变形或弯曲。
要计算物体中的热应力,首先确定其热膨胀或收缩,然后计算应力。
考虑一根长度为 L0。。当加热时,该杆的长度将增加 delta 'L' ,可计算杆长度的分数变化。
现在,将同一根杆的两端固定。当施加热量时,由于杆无法自由膨胀,因而会产生应变。为了恢复杆的原始长度,可以计算所需的应力。
根据杨氏模量的定义,它是应力与应变的比值...
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