Casing wear and casing corrosion are serious problems affecting casing integrity failure in deep and ultra-deep wells.This paper aims to predict the casing burst strength with considerations of both wear and corrosion...Casing wear and casing corrosion are serious problems affecting casing integrity failure in deep and ultra-deep wells.This paper aims to predict the casing burst strength with considerations of both wear and corrosion.Firstly,the crescent wear shape is simplified into three categories according to common mathematical models.Then,based on the mechano-electrochemical(M-E)interaction,the prediction model of corrosion depth is built with worn depth as the initial condition,and the prediction models of burst strength of the worn casing and corroded casing are obtained.Secondly,the accuracy of different prediction models is validated by numerical simulation,and the main influence factors on casing strength are obtained.At last,the theoretical models are applied to an ultra-deep well in Northwest China,and the dangerous well sections caused by wear and corrosion are predicted,and the corrosion rate threshold to ensure the safety of casing is obtained.The results show that the existence of wear defects results in a stress concentration and enhanced M-E interaction on corrosion depth growth.The accuracy of different mathematical models is different:the slot ring model is most accurate for predicting corrosion depth,and the eccentric model is most accurate for predicting the burst strength of corroded casing.The burst strength of the casing will be overestimated by more than one-third if the M-E interaction is neglected,so the coupling effect of wear and corrosion should be sufficiently considered in casing integrity evaluation.展开更多
A corrosion defect is recognized as one of the most severe phenomena for high-pressure pipelines,especially those served for a long time.Finite-element method and empirical formulas are thereby used for the strength p...A corrosion defect is recognized as one of the most severe phenomena for high-pressure pipelines,especially those served for a long time.Finite-element method and empirical formulas are thereby used for the strength prediction of such pipes with corrosion.However,it is time-consuming for finite-element method and there is a limited application range by using empirical formulas.In order to improve the prediction of strength,this paper investigates the burst pressure of line pipelines with a single corrosion defect subjected to internal pressure based on data-driven methods.Three supervised ML(machine learning)algorithms,including the ANN(artificial neural network),the SVM(support vector machine)and the LR(linear regression),are deployed to train models based on experimental data.Data analysis is first conducted to determine proper pipe features for training.Hyperparameter tuning to control the learning process is then performed to fit the best strength models for corroded pipelines.Among all the proposed data-driven models,the ANN model with three neural layers has the highest training accuracy,but also presents the largest variance.The SVM model provides both high training accuracy and high validation accuracy.The LR model has the best performance in terms of generalization ability.These models can be served as surrogate models by transfer learning with new coming data in future research,facilitating a sustainable and intelligent decision-making of corroded pipelines.展开更多
On-site investigations consistently show that the rock burst inherent to coal seams varies greatly with coal seam thickness.In this study,impact factors related to coal seam thickness and surrounding rock strength wer...On-site investigations consistently show that the rock burst inherent to coal seams varies greatly with coal seam thickness.In this study,impact factors related to coal seam thickness and surrounding rock strength were analyzed and a corresponding rock burst risk assessment method was constructed.The model reflects the influence of coal seam thickness on the stress distribution of surrounding rock at the roadway.Based on the roadway excavation range,a stress distribution model of surrounding roadway rock is established and the influence of coal seam thickness on rock burst risk is analyzed accordingly.The proposed rock burst risk assessment method is based on the equivalent surrounding rock strength and coal seam bursting liability.The proposed method was tested in a 3500 mining area to find that it yields rock burst risk assessment results as per coal seam thickness that are in accordance with real-world conditions.The results presented here suggest that coal seam thickness is a crucial factor in effective rock burst risk assessment.展开更多
In the framework of the finite deformation theory, the plastic collapse analysis of thin-walled pipes subjected to the internal pressure is conducted on the basis of the unified strength criterion （USC）. An analytic...In the framework of the finite deformation theory, the plastic collapse analysis of thin-walled pipes subjected to the internal pressure is conducted on the basis of the unified strength criterion （USC）. An analytical solution of the burst pressure for pipes with capped ends is derived, which includes the strength differential effect and takes the influence of strength criterion on the burst pressure into account. In addition, a USC- based analytical solution of the burst pressure for end-opened pipes under the internal pressure is obtained. By discussion, it is found that for the end-capped pipes, the influence of different yield criteria and the strength differential effect on the burst pressure are significant, while for the end-opened pipes, the burst pressure is independent of the specific form of the strength criterion and strength difference in tension and compression.展开更多
The bursting strength is an essential quality parameter of knit fabric. The fabric structure, weight, types of fibers, and fiber blend proportion influence the bursting strength parameter. The tenacity of polyester fi...The bursting strength is an essential quality parameter of knit fabric. The fabric structure, weight, types of fibers, and fiber blend proportion influence the bursting strength parameter. The tenacity of polyester fiber is better than cotton and spandex. The study focused on predicting knit fabric bursting strength test value using different fibers (cotton, polyester, and spandex) with varying percentages of the blend ratio. This study used fifteen categories of blended fabrics. The Pearson Correlation and the hypothetical ANOVA regression analysis were conducted to do the statistical significance test. The experimental result reveals that the bursting strength test result increased with the increased percentage of polyester and suggested a suitable regression equation. The dominance of the polyester fiber was observed throughout the experiment, i.e., the higher the polyester blend proportion, the higher the bursting strength value. The inclusion of polyester in blends can reduce the cost of fabric. The developed prediction model or equation can help the fabric manufacturer make appropriate decisions regarding getting the expected bursting strength. The researcher hopes that the findings from this study will motivate new researchers, advanced researchers, and the textile manufacturing industry.展开更多
建立了药用铝箔破裂强度的测量不确定度评定方法,为提升检验结果的科学性与可靠性提供依据。依据2025年版《中国药典》四部通则4055“铝箔物理性能测定法”对药用铝箔进行破裂强度测试,系统分析并量化了测量不确定度的主要来源,计算得...建立了药用铝箔破裂强度的测量不确定度评定方法,为提升检验结果的科学性与可靠性提供依据。依据2025年版《中国药典》四部通则4055“铝箔物理性能测定法”对药用铝箔进行破裂强度测试,系统分析并量化了测量不确定度的主要来源,计算得到合成标准不确定度与扩展不确定度。试验结果显示,样品破裂强度平均值为188.6 kPa,合成标准不确定度为1.5 kPa,扩展不确定度为3.0 k Pa。该方法有助于检验人员客观评估测量结果的可靠程度,为药品包装材料的质量控制与标准化评价提供可靠科学依据。展开更多
为了研究重复用手术衣的耐洗涤性能,评价手术衣的使用寿命,采用由聚酯纤维(PET)针织面料为表层、聚四氟乙烯(PTFE)薄膜为中间层、99%聚酯纤维+1%导电丝针织面料为里层复合的3层手术衣,经洗涤10次、20次、30次、50次、60次后,测试分析其...为了研究重复用手术衣的耐洗涤性能,评价手术衣的使用寿命,采用由聚酯纤维(PET)针织面料为表层、聚四氟乙烯(PTFE)薄膜为中间层、99%聚酯纤维+1%导电丝针织面料为里层复合的3层手术衣,经洗涤10次、20次、30次、50次、60次后,测试分析其洗涤前后抗渗水性、接触角、阻湿态微生物穿透、胀破强力和表面形貌。结果表明:重复用手术衣经60次洗涤后,抗渗水性仍在100 cm H_(2)O以上,干态和湿态胀破强力值在270 kPa以上,保持较高的力学性能;经重复洗涤后,手术衣表面结构疏松,纤维断裂,表面由疏水性转变为亲水性,易被液体渗透,屏障指数没有变化,仍具备在湿态下对细菌的阻隔功能。认为:重复用手术衣的疏水性能有显著变化,生产企业要关注表面处理工艺,提高材料的耐洗消性能;要根据实际验证结果确定洗消次数,确保产品在全生命周期中的安全有效性。展开更多
文摘Casing wear and casing corrosion are serious problems affecting casing integrity failure in deep and ultra-deep wells.This paper aims to predict the casing burst strength with considerations of both wear and corrosion.Firstly,the crescent wear shape is simplified into three categories according to common mathematical models.Then,based on the mechano-electrochemical(M-E)interaction,the prediction model of corrosion depth is built with worn depth as the initial condition,and the prediction models of burst strength of the worn casing and corroded casing are obtained.Secondly,the accuracy of different prediction models is validated by numerical simulation,and the main influence factors on casing strength are obtained.At last,the theoretical models are applied to an ultra-deep well in Northwest China,and the dangerous well sections caused by wear and corrosion are predicted,and the corrosion rate threshold to ensure the safety of casing is obtained.The results show that the existence of wear defects results in a stress concentration and enhanced M-E interaction on corrosion depth growth.The accuracy of different mathematical models is different:the slot ring model is most accurate for predicting corrosion depth,and the eccentric model is most accurate for predicting the burst strength of corroded casing.The burst strength of the casing will be overestimated by more than one-third if the M-E interaction is neglected,so the coupling effect of wear and corrosion should be sufficiently considered in casing integrity evaluation.
文摘A corrosion defect is recognized as one of the most severe phenomena for high-pressure pipelines,especially those served for a long time.Finite-element method and empirical formulas are thereby used for the strength prediction of such pipes with corrosion.However,it is time-consuming for finite-element method and there is a limited application range by using empirical formulas.In order to improve the prediction of strength,this paper investigates the burst pressure of line pipelines with a single corrosion defect subjected to internal pressure based on data-driven methods.Three supervised ML(machine learning)algorithms,including the ANN(artificial neural network),the SVM(support vector machine)and the LR(linear regression),are deployed to train models based on experimental data.Data analysis is first conducted to determine proper pipe features for training.Hyperparameter tuning to control the learning process is then performed to fit the best strength models for corroded pipelines.Among all the proposed data-driven models,the ANN model with three neural layers has the highest training accuracy,but also presents the largest variance.The SVM model provides both high training accuracy and high validation accuracy.The LR model has the best performance in terms of generalization ability.These models can be served as surrogate models by transfer learning with new coming data in future research,facilitating a sustainable and intelligent decision-making of corroded pipelines.
基金supported and financed from Special Funds for Basic Research Business Fees of China Academy of Safety Science and Technology(Nos.2016JBKY16,2017JBKY05)National Key Research and Development Program of China(No.2017YFC0804603)Subject of Beijing Science and Technology Commission(No.Z171100002317008)
文摘On-site investigations consistently show that the rock burst inherent to coal seams varies greatly with coal seam thickness.In this study,impact factors related to coal seam thickness and surrounding rock strength were analyzed and a corresponding rock burst risk assessment method was constructed.The model reflects the influence of coal seam thickness on the stress distribution of surrounding rock at the roadway.Based on the roadway excavation range,a stress distribution model of surrounding roadway rock is established and the influence of coal seam thickness on rock burst risk is analyzed accordingly.The proposed rock burst risk assessment method is based on the equivalent surrounding rock strength and coal seam bursting liability.The proposed method was tested in a 3500 mining area to find that it yields rock burst risk assessment results as per coal seam thickness that are in accordance with real-world conditions.The results presented here suggest that coal seam thickness is a crucial factor in effective rock burst risk assessment.
基金Project supported by the National Natural Science Foundation of China (Nos. 51079128 and11172265)the Natural Science Foundation of Zhejiang Province of China (No. Y1101107)
文摘In the framework of the finite deformation theory, the plastic collapse analysis of thin-walled pipes subjected to the internal pressure is conducted on the basis of the unified strength criterion （USC）. An analytical solution of the burst pressure for pipes with capped ends is derived, which includes the strength differential effect and takes the influence of strength criterion on the burst pressure into account. In addition, a USC- based analytical solution of the burst pressure for end-opened pipes under the internal pressure is obtained. By discussion, it is found that for the end-capped pipes, the influence of different yield criteria and the strength differential effect on the burst pressure are significant, while for the end-opened pipes, the burst pressure is independent of the specific form of the strength criterion and strength difference in tension and compression.
文摘The bursting strength is an essential quality parameter of knit fabric. The fabric structure, weight, types of fibers, and fiber blend proportion influence the bursting strength parameter. The tenacity of polyester fiber is better than cotton and spandex. The study focused on predicting knit fabric bursting strength test value using different fibers (cotton, polyester, and spandex) with varying percentages of the blend ratio. This study used fifteen categories of blended fabrics. The Pearson Correlation and the hypothetical ANOVA regression analysis were conducted to do the statistical significance test. The experimental result reveals that the bursting strength test result increased with the increased percentage of polyester and suggested a suitable regression equation. The dominance of the polyester fiber was observed throughout the experiment, i.e., the higher the polyester blend proportion, the higher the bursting strength value. The inclusion of polyester in blends can reduce the cost of fabric. The developed prediction model or equation can help the fabric manufacturer make appropriate decisions regarding getting the expected bursting strength. The researcher hopes that the findings from this study will motivate new researchers, advanced researchers, and the textile manufacturing industry.
文摘建立了药用铝箔破裂强度的测量不确定度评定方法,为提升检验结果的科学性与可靠性提供依据。依据2025年版《中国药典》四部通则4055“铝箔物理性能测定法”对药用铝箔进行破裂强度测试,系统分析并量化了测量不确定度的主要来源,计算得到合成标准不确定度与扩展不确定度。试验结果显示,样品破裂强度平均值为188.6 kPa,合成标准不确定度为1.5 kPa,扩展不确定度为3.0 k Pa。该方法有助于检验人员客观评估测量结果的可靠程度,为药品包装材料的质量控制与标准化评价提供可靠科学依据。
文摘为了研究重复用手术衣的耐洗涤性能,评价手术衣的使用寿命,采用由聚酯纤维(PET)针织面料为表层、聚四氟乙烯(PTFE)薄膜为中间层、99%聚酯纤维+1%导电丝针织面料为里层复合的3层手术衣,经洗涤10次、20次、30次、50次、60次后,测试分析其洗涤前后抗渗水性、接触角、阻湿态微生物穿透、胀破强力和表面形貌。结果表明:重复用手术衣经60次洗涤后,抗渗水性仍在100 cm H_(2)O以上,干态和湿态胀破强力值在270 kPa以上,保持较高的力学性能;经重复洗涤后,手术衣表面结构疏松,纤维断裂,表面由疏水性转变为亲水性,易被液体渗透,屏障指数没有变化,仍具备在湿态下对细菌的阻隔功能。认为:重复用手术衣的疏水性能有显著变化,生产企业要关注表面处理工艺,提高材料的耐洗消性能;要根据实际验证结果确定洗消次数,确保产品在全生命周期中的安全有效性。
