基于无损检测的超役黄杉和杉木构件的剩余强度分析

Residual strength of service-beyond wood members of douglas fir and cedarwood using non-destructive testing

为了评估超役木构件的损伤状况,确定其剩余强度,对东南大学老图书馆维修加固拆卸下来的一批木梁柱构件进行无损检测、材性试验研究。首先目测该批超役木构件的腐朽和虫蛀等级,利用射钉仪和木材阻抗仪,对木材的腐朽和虫蛀状况进行无损检测,并对2种仪器的检测结果进行相关性分析。然后截取小段构件制成小试件进行材性试验,包括顺纹抗压强度、顺纹抗拉强度,拟合出小试件强度和阻力之间的关系曲线;将剩余大段构件其余测点的阻力代入关系曲线,得到考虑腐朽和虫蛀影响的小试件强度。分析小试件强度和构件强度的差别,最终得到考虑腐朽和虫蛀影响的构件剩余强度。结果表明:目测分级大体可行,但部分测点目测等级不可靠;构件剩余抗拉强度和剩余抗压强度分别为15.31～25.89 MPa和8.46～13.73 MPa。

To check service-beyond wood members and determine their residual strength,researches on non-destructive testing techniques and mechanical tests of service-beyond wood members coming from the old library of Southeast University were carried out.First of all,the decadent and eaten levels of these members were viewed.Nail gun and Resistograph were used to test the decay and bitten damages.The correlations between the two kinds of instrument test data were researched.Secondly,small timber specimens were used to do mechanical tests,including the compressive strength and the tensile strength.The relationship between the small specimen＇s strength and the resistance values were fitted to curves.According to these curves,the residual strength of small timber specimens was computed.After knowing the differences between small timber specimens and wood members,the residual strength of these wood members are obtained eventually.The results show that classification by sight is feasible in general except some measure points.The residual tensile strengths and compressive strengths of these members are 15.31？25.89 MPa and 8.46？13.73 MPa,respectively.