In the aerospace field, residual stress directly affects the strength, fatigue life and dimensional stability of thin-walled structural components, and is a key factor to ensure flight safety and reliability. At prese...In the aerospace field, residual stress directly affects the strength, fatigue life and dimensional stability of thin-walled structural components, and is a key factor to ensure flight safety and reliability. At present, research on residual stress at home and abroad mainly focuses on the optimization of traditional detection technology, stress control of manufacturing process and service performance evaluation, among which research on residual stress detection methods mainly focuses on the improvement of the accuracy, sensitivity, reliability and other performance of existing detection methods, but it still faces many challenges such as extremely small detection range, low efficiency, large error and limited application range.展开更多
With the increasing utilization of liquefied natural gas(LNG)as a marine fuel,the safety and reliability of shore-based LNG bunkering operations have become vital concerns.Human factors are crucial to the successful e...With the increasing utilization of liquefied natural gas(LNG)as a marine fuel,the safety and reliability of shore-based LNG bunkering operations have become vital concerns.Human factors are crucial to the successful execution of these operations.However,predicting human reliability in such complex scenarios remains challenging.This paper focuses on the prediction of human reliability analysis(HRA)for shorebased LNG bunkering operations on tanker ships to address the aforementioned gap.Practical approaches to predicting HRA under the success likelihood index method(SLIM)and an improved Z-numbers approach are both adopted in this paper.SLIM provides a powerful tool to calculate human error,while the improved Z-numbers can address uncertainty and improve the reliability of qualitative expert judgments.Results show that the reliability of shore-based LNG bunkering operations is 0.861.In addition to its robust theoretical contribution,this research provides substantial practical contributions to LNG ship owners,ship superintendents,safety inspectors,and shore-based and ship crew for enhancing safety at the operational level and efficiency of shore-based LNG bunkering operations.展开更多
The study of artificial slope stability has been a key item of geological engineering projects. Though more evaluation methods are available,result of stability evaluation simulation does not explain the actual proble...The study of artificial slope stability has been a key item of geological engineering projects. Though more evaluation methods are available,result of stability evaluation simulation does not explain the actual problem owing to the diversified geological engineering factors and complexity. The author made a detailed study based on surveys of large amount of geological engineering research on Donggang Power Plant slope project,discussed the comprehensive factors influencing the project,and gave analytical calculation and evaluation to the improved response surface of the slope project. The study result shows that the slope is stable,which can provide scientific basis for designing the slope.展开更多
This paper investigates the reliability of composite laminates with various lay-ups under fatigue loading.The prediction of failure probability of composite laminates subjected to different loads involves many uncerta...This paper investigates the reliability of composite laminates with various lay-ups under fatigue loading.The prediction of failure probability of composite laminates subjected to different loads involves many uncertainties associated with mechanical properties,loading,and boundary conditions.Failure in the composite material is truly hard to trace because there are individual faults in each ply,and we face a stochastic process due to the scatter in the mechanical properties.The continuum damage mechanics(CDM),as a powerful approach,is applied to model the damage of fiber,matrix,and fiber/matrix debonding.This method defines criteria for damage detection and determines safe zones.The material constitutive equations are executed using a subroutine inAbaqus.The first-order reliability method and second-order reliability method have been applied to examine the reliability of laminated composites.The results are compared with those of the Monte Carlo simulation.Different composite laminates under different stress levels are considered for the failure probability investigation.The limit state functions and random variables have been determined based on the CDM model.Finally,the effects of the number of cycles,applied stress,and stacking sequence of the laminate on the reliability and fatigue life in fiber-reinforced laminated composites are assessed.展开更多
对多旋翼电动垂直起降(electric vertical takeoff and landing,eVTOL)航空器推进系统进行了可靠性分析与分配。首先,针对多旋翼eVTOL航空器可靠性历史数据积累不足的问题,使用模糊贝叶斯网络(fuzzy Bayesian network,FBN)建立可靠性分...对多旋翼电动垂直起降(electric vertical takeoff and landing,eVTOL)航空器推进系统进行了可靠性分析与分配。首先,针对多旋翼eVTOL航空器可靠性历史数据积累不足的问题,使用模糊贝叶斯网络(fuzzy Bayesian network,FBN)建立可靠性分析模型,对其可靠性先验数据进行了补充,并进行可靠性后验推理,辅助定位推进系统关键环节。其次,基于FBN可靠性分析模型,提出一种改进电子设备可靠性咨询组(advisory group on reliability of electronic equipment,AGREE)可靠性分配方法,对不同构型多旋翼eVTOL推进系统进行可靠性分配。结果表明,FBN可靠性分析模型补充了推进系统可靠性数据,可有效识别系统薄弱环节。改进AGREE分配法的可靠性分配结果符合SC-VTOL-01中对eVTOL航空器的可靠性要求,同时该方法得到的可靠性分配结果更为合理,体现了不同构型、子系统、部件间的差异。展开更多
文摘In the aerospace field, residual stress directly affects the strength, fatigue life and dimensional stability of thin-walled structural components, and is a key factor to ensure flight safety and reliability. At present, research on residual stress at home and abroad mainly focuses on the optimization of traditional detection technology, stress control of manufacturing process and service performance evaluation, among which research on residual stress detection methods mainly focuses on the improvement of the accuracy, sensitivity, reliability and other performance of existing detection methods, but it still faces many challenges such as extremely small detection range, low efficiency, large error and limited application range.
文摘With the increasing utilization of liquefied natural gas(LNG)as a marine fuel,the safety and reliability of shore-based LNG bunkering operations have become vital concerns.Human factors are crucial to the successful execution of these operations.However,predicting human reliability in such complex scenarios remains challenging.This paper focuses on the prediction of human reliability analysis(HRA)for shorebased LNG bunkering operations on tanker ships to address the aforementioned gap.Practical approaches to predicting HRA under the success likelihood index method(SLIM)and an improved Z-numbers approach are both adopted in this paper.SLIM provides a powerful tool to calculate human error,while the improved Z-numbers can address uncertainty and improve the reliability of qualitative expert judgments.Results show that the reliability of shore-based LNG bunkering operations is 0.861.In addition to its robust theoretical contribution,this research provides substantial practical contributions to LNG ship owners,ship superintendents,safety inspectors,and shore-based and ship crew for enhancing safety at the operational level and efficiency of shore-based LNG bunkering operations.
文摘The study of artificial slope stability has been a key item of geological engineering projects. Though more evaluation methods are available,result of stability evaluation simulation does not explain the actual problem owing to the diversified geological engineering factors and complexity. The author made a detailed study based on surveys of large amount of geological engineering research on Donggang Power Plant slope project,discussed the comprehensive factors influencing the project,and gave analytical calculation and evaluation to the improved response surface of the slope project. The study result shows that the slope is stable,which can provide scientific basis for designing the slope.
文摘This paper investigates the reliability of composite laminates with various lay-ups under fatigue loading.The prediction of failure probability of composite laminates subjected to different loads involves many uncertainties associated with mechanical properties,loading,and boundary conditions.Failure in the composite material is truly hard to trace because there are individual faults in each ply,and we face a stochastic process due to the scatter in the mechanical properties.The continuum damage mechanics(CDM),as a powerful approach,is applied to model the damage of fiber,matrix,and fiber/matrix debonding.This method defines criteria for damage detection and determines safe zones.The material constitutive equations are executed using a subroutine inAbaqus.The first-order reliability method and second-order reliability method have been applied to examine the reliability of laminated composites.The results are compared with those of the Monte Carlo simulation.Different composite laminates under different stress levels are considered for the failure probability investigation.The limit state functions and random variables have been determined based on the CDM model.Finally,the effects of the number of cycles,applied stress,and stacking sequence of the laminate on the reliability and fatigue life in fiber-reinforced laminated composites are assessed.
文摘对多旋翼电动垂直起降(electric vertical takeoff and landing,eVTOL)航空器推进系统进行了可靠性分析与分配。首先,针对多旋翼eVTOL航空器可靠性历史数据积累不足的问题,使用模糊贝叶斯网络(fuzzy Bayesian network,FBN)建立可靠性分析模型,对其可靠性先验数据进行了补充,并进行可靠性后验推理,辅助定位推进系统关键环节。其次,基于FBN可靠性分析模型,提出一种改进电子设备可靠性咨询组(advisory group on reliability of electronic equipment,AGREE)可靠性分配方法,对不同构型多旋翼eVTOL推进系统进行可靠性分配。结果表明,FBN可靠性分析模型补充了推进系统可靠性数据,可有效识别系统薄弱环节。改进AGREE分配法的可靠性分配结果符合SC-VTOL-01中对eVTOL航空器的可靠性要求,同时该方法得到的可靠性分配结果更为合理,体现了不同构型、子系统、部件间的差异。
