【摘要】：復(fù)雜的環(huán)境載荷不可避免地會造成海洋結(jié)構(gòu)物的疲勞損傷,而高強(qiáng)度厚鋼板典型的三向應(yīng)力狀態(tài)會增加結(jié)構(gòu)脆性,更加縮短結(jié)構(gòu)的疲勞壽命。為研究厚板裂紋前緣應(yīng)力狀態(tài)沿板厚方向的分布,完成了3組36 mm板厚Q370QE高強(qiáng)度鋼的標(biāo)準(zhǔn)疲勞裂紋擴(kuò)展速率試驗,得到了材料參數(shù)C,m以及應(yīng)力強(qiáng)度因子門檻值。接著,應(yīng)用有限元方法分別基于線彈性分析和塑性分析計算裂紋尖端應(yīng)力強(qiáng)度因子和裂紋尖端局部約束因子,并解釋試驗中裂紋前緣由傾斜趨于平直的現(xiàn)象。計算所得裂紋尖端應(yīng)力強(qiáng)度因子可描述板厚中心部分裂紋前緣的應(yīng)力狀態(tài),但在試件表面處結(jié)果失真,而裂紋前緣局部約束因子因考慮了厚板的厚度效應(yīng),故沿板厚方向分布的裂紋尖端局部約束因子可有效量化裂紋尖端的應(yīng)力狀態(tài)分布。
[Abstract]:Complex environmental loads will inevitably cause fatigue damage of offshore structures, while the typical triaxial stress state of high strength thick steel plates will increase the structural brittleness and shorten the fatigue life of the structures. In order to study the distribution of crack front stress state along the thickness direction of thick plate, three groups of standard fatigue crack growth rate tests of 36 mm thick Q370QE high strength steel have been completed. The material parameter Cumm and the threshold value of stress intensity factor have been obtained. Then the stress intensity factor and the local constraint factor at the crack tip are calculated based on the linear elastic analysis and the plastic analysis, respectively, and the phenomenon that the cause of the crack tends to be straight is explained in the experiment. The calculated stress intensity factor at the crack tip can describe the stress state of the crack front in the thick center of the plate, but the results are distorted on the surface of the specimen, and the thickness effect of the thick plate is taken into account in the local constraint factor of the crack front. Therefore, the stress state distribution at the crack tip can be effectively quantified by the local constraint factor distributed along the plate thickness direction.
【作者單位】： 武漢理工大學(xué)交通學(xué)院;
【基金】：國家自然科學(xué)基金資助項目(51009111) 中央高校基本科研業(yè)務(wù)費專項資金資助項目(135202006)
【分類號】：U661.4

【相似文獻(xiàn)】

相關(guān)期刊論文 前1條

1 孫欣;鄰近肋骨對錐柱結(jié)合殼應(yīng)力狀態(tài)的影響[J];艦船科學(xué)技術(shù);1979年02期

，

本文編號：2379825