什么叫应力测试
请问什么叫应力测试 我们这里有测试配管应力，但具体不知道怎么解释 应力：当材料在外力作用下不能产生位移时，它的几何形状和尺寸将发生变化，这种形变称为应变(Strain)。材料发生形变时内部产生了大小相等但方向相反的反作用力抵抗外力，定义单位面积上的这种反作用力为应力(Sress)。按照应力和应变的方向关系，可以将应力分为正应力σ和切应力τ，正应力的方向与应变方向平行，而切应力的方向与应变垂直。按照载荷(Load)作用的形式不同，应力又可以分为拉伸压缩应力、弯曲应力和扭转应力。(------引自百度百科)自然对应力的测试就叫应力测试。不同产品，不同材料，应力的测试方法和仪器各有不同。 在标准上有没有对“应力”的定义？
UL1598 Ver. 2.0
16.4 Mold stress relief16.4.1 A sample of the complete thermoplastic enclosure shall be placed in a circulating air oven and
maintained at a temperature 10 °C higher than the maximum temperature measured on the surface of the
enclosure during the normal temperature test but in no case less than 70 °C, for a period of 7 h.
16.4.2 After the sample has cooled to room temperature, the sample shall comply with the applicable
requirements of this Standard. EN60950-1:2006
4.2.7 Stress relief test
ENCLOSURES of moulded or formed thermoplastic materials shall be so constructed that any
shrinkage or distortion of the material due to release of internal stresses caused by the
moulding or forming operation does not result in the exposure of hazardous parts or in the
reduction of CLEARANCES or CREEPAGE DISTANCES below the values specified in 2.10 (or
Annex G).
Compliance is checked by the test procedure described below or by the inspection of the
construction and the available data where appropriate.
One sample consisting of the complete equipment, or of the complete ENCLOSURE together
with any supporting framework, is placed in a circulating air oven (according to
IEC 60216-4-1) at a temperature 10 K higher than the maximum temperature observed on the
ENCLOSURE during the test of 4.5.2, but not less than 70 ° C, for a period of 7 h, then permitted
to cool to room temperature.
With the concurrence of the manufacturer, it is permitted to increase the above time duration.
For large equipment where it is impractical to condition a complete ENCLOSURE, it is permitted
to use a portion of the ENCLOSURE representative of the complete assembly with regard to
thickness and shape, including any mechanical support members.
NOTE Relative humidity need not be maintained at a specific value during this test.
If the above test is conducted, the compliance criteria of 4.2.1 apply. 通俗点就是拉电源线的卡口，看是不是很耐用！！我们公司是这样测 的~ 有沒有辦法對應力進行計算?
比如說材質不同,它的應力系數是多少等等....
能否請一并提供此類資料,謝謝.. 可以查材料手册和参看材料力学等书籍 对于电源线，我们在电线和线芯上打上标记，再用156N的力拉1分钟，再根据标记的位置来确定电源线与线夹相对移动的距离和线芯与电源线外皮相对移动的距离来判断电源线有没有受到应力。
