allowable bond unitstress

例句：

1. 1. The engineer used the unit stress formula to calculate the material's strength.
   工程师使用单位应力公式来计算材料的强度。
2. 2. The construction company was required to maintain a certain level of unit strain in their work.
   建筑公司被要求保持一定的单位应变水平。
3. 3. The scientist discovered that the unit force exerted by gravity on an object is directly proportional to its mass.
   科学家发现，物体受到的重力单位力与其质量成正比。