【摘要】：為提高管道凹坑缺陷應(yīng)變評(píng)估方法的準(zhǔn)確性,基于韌性斷裂模型和損傷力學(xué),建立管道凹坑損傷評(píng)估模型。結(jié)合有限元方法,研究2種典型凹坑缺陷(平滑型凹坑和曲折型凹坑)不同區(qū)域的損傷程度,計(jì)算在不同管規(guī)格和內(nèi)壓下的凹坑缺陷臨界失效應(yīng)變。數(shù)值模擬結(jié)果表明:不同類型凹坑的各部位損傷程度不同,且可能產(chǎn)生裂紋的部位也不同;不同管規(guī)格之間的臨界失效應(yīng)變差別較小;由于內(nèi)壓的回彈作用,不同內(nèi)壓下的非約束型凹坑的臨界失效應(yīng)變不同,可進(jìn)而得到內(nèi)壓和臨界失效應(yīng)變的擬合關(guān)系;凹坑缺陷的應(yīng)變評(píng)估需要將凹坑分為約束型和非約束型,選用不同的應(yīng)變標(biāo)準(zhǔn)分別予以評(píng)估。
[Abstract]:In order to improve the accuracy of the method for evaluating the defect and strain of the pipe pit, the damage assessment model of the pipe is established based on the ductile fracture model and damage mechanics. Combined with finite element method, the damage degree in different regions of two typical concave defects (smooth and zigzag pits) is studied, and the critical failure strain of concave defects under different pipe specifications and internal pressure is calculated. The results of numerical simulation show that the damage degree of different types of pits is different and the positions where cracks may occur are different, and the critical failure strain difference between different pipe specifications is relatively small. Due to the springback of internal pressure, the critical failure strain of unconstrained pit under different internal pressure is different, and the fitting relationship between internal pressure and critical failure strain can be obtained. The strain assessment of pit defects needs to be divided into constrained and unconstrained types, and different strain criteria should be selected to evaluate them.
【作者單位】： 中國石化天然氣榆濟(jì)管道分公司;中石化中原天然氣有限責(zé)任公司;
【分類號(hào)】：TE973
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本文編號(hào)：2336627