通过动态电阻应变仪对加热—冷却过程毛竹的弦向应变特性进行了检测和分析。结果表明：在加热过程中竹材的弦向应变大体呈抛物线状变化，在80 ℃以前，随温度上升正应变逐渐增加，而后正应变逐渐减小，超过120 ℃后成为负应变。在冷却过程中，从150 ℃下降到100 ℃时，竹材的弦向应变变化不大，从100 ℃下降到30 ℃时负应变大幅增加。在加热和冷却过程中，对应同一温度的各试件弦向应变差异较大，表现出多分散性。竹材加热—冷却过程中形成的应力会使竹材表面产生扩张与皱缩应变，这种应变会导致竹材表面粗糙度增加。

The tangential strains of bamboo in the process of heating and cooling were investigated through dynamic resistance strain gauge. Test results showed that the change of the tangential strain of bamboo with temperature presented mainly parabolic curve form, positive strains gradually increased below 80 ℃，and then decreased gradually，changed into negative strain after 120 ℃ in the process of heating. In the process of cooling the negative tangential strain of bamboo increased slowly from 150 ℃ to 100 ℃，and then rapidly increased from 100 ℃ to 30 ℃. In the process of heating and cooling the tangential strain of each piece was obviously different at the same temperature. The strain presented in the process of heating and cooling would increase the surface roughness degree of bamboo.