When a hydrogen storage vessel is subjected to a local impact load, damage may occur in the liner and result in hydrogen leakage and other catastrophic consequences. When predicting liner damage of a hydrogen storage ...When a hydrogen storage vessel is subjected to a local impact load, damage may occur in the liner and result in hydrogen leakage and other catastrophic consequences. When predicting liner damage of a hydrogen storage vessel using the finite element method(FEM), although large element size is required to achieve a desired computational efficiency, it oftentimes causes inaccuracy in the damage model. To remedy this problem, in this study a novel approach which calculates the material damage based on the GISSMO(Generalized Incremental Stress State dependent damage Model) damage model and employs a submodeling strategy is proposed. According to this approach,the global model is discretized to large elements to increase the efficiency, while the submodel is meshed to much smaller elements to accurately reflect the material damage. Employing the established approach and material parameters calibrated from a large set of notched aluminum alloy 5083 specimens, the liner damage of a type Ⅲ hydrogen storage vessel subjected to a local compressive load was simulated. This way, the study reveals how the characteristics of the stress and material damage interact with each other. In addition, the study also demonstrates that the proposed approach can be used as a viable means to evaluate the damage within hydrogen storage vessels.展开更多
A submodel method was proposed that works from computational models of marine gear cases to verify that the proposed bolts will give it sufficient structural integrity. Calculations for marine equipment using this sys...A submodel method was proposed that works from computational models of marine gear cases to verify that the proposed bolts will give it sufficient structural integrity. Calculations for marine equipment using this system accorded well with conventional results. As an example, an anti-shock computation was processed for a gear case, and the submodel was then employed to check the strength of individual components. The results showed that the gear case connecting structure can satisfy relative anti-shock requirements, and the dynamic response characteristics seen in the bolt structures had a close relationship with the method used for attaching the bolt. This provides a new means for checking the strength of connecting structures on large-scale equipment and thus has significant reference value.展开更多
为研究浮式生产储卸油装置(floating production storage and offloading,FPSO)浮筒关键节点的疲劳强度问题,本文基于FPSO三舱段、浮筒锥体、浮筒转塔、锥形对接模块(mating cone module,MCM)的整体模型,通过应力分析确定出应力较为集...为研究浮式生产储卸油装置(floating production storage and offloading,FPSO)浮筒关键节点的疲劳强度问题,本文基于FPSO三舱段、浮筒锥体、浮筒转塔、锥形对接模块(mating cone module,MCM)的整体模型,通过应力分析确定出应力较为集中的区域并作为热点,建立精细化网格的子模型以获得热点应力。基于力传递函数的方法,根据规范开展浮筒和MCM的疲劳简化分析,研究系泊和立管载荷对浮筒局部结构的疲劳影响。结果表明,浮筒锥体、浮筒转塔和MCM中关键节点的疲劳强度均满足设计疲劳强度要求,其中最薄弱的热点结构HS1的疲劳寿命为3262 a,大于20 a的设计寿命,满足FPSO单点系泊浮筒的设计预期要求。展开更多
Runyang Suspension Bridge (RSB) with the main span of 1490 m is the longest bridge in China and the third longest one in the world. In this bridge the rigid central buckle is employed for the first time in the mid-spa...Runyang Suspension Bridge (RSB) with the main span of 1490 m is the longest bridge in China and the third longest one in the world. In this bridge the rigid central buckle is employed for the first time in the mid-span of the suspension bridge in China. For such a super-long-span bridge, the traditional finite element (FE) modeling technique and stress analysis methods obviously cannot satisfy the needs of conducting accurate stress analysis on the central buckle. In this paper, the submodel method is in- troduced and for the first time used in analyzing the stresses of the central buckle. After an accurate FE submodel of the central buckle was specially established according to the analysis results from the whole FE model, the connection technique between the two-scale FE models was realized and the ac- curate stresses of the central buckle under various vehicle load cases were then conducted based on the submodel method. The calculation results were testified to be accurate and reliable by the field measurements, which show the efficiency and reliability of the submodel method on analyzing the mechanical condition of the central buckle of long-span suspension bridges. Finally, the working be- havior and mechanical characteristics of the central buckle of the RSB under vehicle loads were ana- lyzed based on the calculation and measurement results. The results obtained in this paper can provide theoretic references for analyzing and designing the rigid central buckle in long-span suspension bridges in future.展开更多
激光干涉空间天线LISA(laser interferometer space antenna)作为空间引力波探测任务装备,其结构的轻量化设计是重要问题之一。基于子模型分析技术,采用固体各向同性材料惩罚(SIMP)模型插值变密度法,对LISA中肘杆机构的上下肘杆进行了...激光干涉空间天线LISA(laser interferometer space antenna)作为空间引力波探测任务装备,其结构的轻量化设计是重要问题之一。基于子模型分析技术,采用固体各向同性材料惩罚(SIMP)模型插值变密度法,对LISA中肘杆机构的上下肘杆进行了拓扑优化设计;将肘杆的应力作为约束条件,并以肘杆结构的柔度最小化和质量最小化为优化目标,构建肘杆拓扑优化的数学模型,得到了肘杆构件的最优拓扑结构。优化后的上下肘杆质量分别降低了41.89%和32.31%,且优化后的肘杆机构应力和位移均满足设计要求,为进一步设计和实验研究提供参考。展开更多
基金Supported by National Natural Science Foundation of China (Grant No. 52172353)。
文摘When a hydrogen storage vessel is subjected to a local impact load, damage may occur in the liner and result in hydrogen leakage and other catastrophic consequences. When predicting liner damage of a hydrogen storage vessel using the finite element method(FEM), although large element size is required to achieve a desired computational efficiency, it oftentimes causes inaccuracy in the damage model. To remedy this problem, in this study a novel approach which calculates the material damage based on the GISSMO(Generalized Incremental Stress State dependent damage Model) damage model and employs a submodeling strategy is proposed. According to this approach,the global model is discretized to large elements to increase the efficiency, while the submodel is meshed to much smaller elements to accurately reflect the material damage. Employing the established approach and material parameters calibrated from a large set of notched aluminum alloy 5083 specimens, the liner damage of a type Ⅲ hydrogen storage vessel subjected to a local compressive load was simulated. This way, the study reveals how the characteristics of the stress and material damage interact with each other. In addition, the study also demonstrates that the proposed approach can be used as a viable means to evaluate the damage within hydrogen storage vessels.
基金Supported by the Shipbuilding Industry of National Defense Science and Technology Research Projects in Advance (07J1.5.3)
文摘A submodel method was proposed that works from computational models of marine gear cases to verify that the proposed bolts will give it sufficient structural integrity. Calculations for marine equipment using this system accorded well with conventional results. As an example, an anti-shock computation was processed for a gear case, and the submodel was then employed to check the strength of individual components. The results showed that the gear case connecting structure can satisfy relative anti-shock requirements, and the dynamic response characteristics seen in the bolt structures had a close relationship with the method used for attaching the bolt. This provides a new means for checking the strength of connecting structures on large-scale equipment and thus has significant reference value.
文摘为研究浮式生产储卸油装置(floating production storage and offloading,FPSO)浮筒关键节点的疲劳强度问题,本文基于FPSO三舱段、浮筒锥体、浮筒转塔、锥形对接模块(mating cone module,MCM)的整体模型,通过应力分析确定出应力较为集中的区域并作为热点,建立精细化网格的子模型以获得热点应力。基于力传递函数的方法,根据规范开展浮筒和MCM的疲劳简化分析,研究系泊和立管载荷对浮筒局部结构的疲劳影响。结果表明,浮筒锥体、浮筒转塔和MCM中关键节点的疲劳强度均满足设计疲劳强度要求,其中最薄弱的热点结构HS1的疲劳寿命为3262 a,大于20 a的设计寿命,满足FPSO单点系泊浮筒的设计预期要求。
基金Supported by the National High Technology Research and Development Program ("863" Project) (Grant No. 2006AA04Z416)the Key Project of the National Natural Science Foundation of China (Grant No. 50538020)+1 种基金the National Natural Science Foundation of China for Young Scholars (Grant No. 50608017) the Ph.D. Pro-grams Foundation of Ministry of Education of China (Grant No. 200802861012)
文摘Runyang Suspension Bridge (RSB) with the main span of 1490 m is the longest bridge in China and the third longest one in the world. In this bridge the rigid central buckle is employed for the first time in the mid-span of the suspension bridge in China. For such a super-long-span bridge, the traditional finite element (FE) modeling technique and stress analysis methods obviously cannot satisfy the needs of conducting accurate stress analysis on the central buckle. In this paper, the submodel method is in- troduced and for the first time used in analyzing the stresses of the central buckle. After an accurate FE submodel of the central buckle was specially established according to the analysis results from the whole FE model, the connection technique between the two-scale FE models was realized and the ac- curate stresses of the central buckle under various vehicle load cases were then conducted based on the submodel method. The calculation results were testified to be accurate and reliable by the field measurements, which show the efficiency and reliability of the submodel method on analyzing the mechanical condition of the central buckle of long-span suspension bridges. Finally, the working be- havior and mechanical characteristics of the central buckle of the RSB under vehicle loads were ana- lyzed based on the calculation and measurement results. The results obtained in this paper can provide theoretic references for analyzing and designing the rigid central buckle in long-span suspension bridges in future.
文摘激光干涉空间天线LISA(laser interferometer space antenna)作为空间引力波探测任务装备,其结构的轻量化设计是重要问题之一。基于子模型分析技术,采用固体各向同性材料惩罚(SIMP)模型插值变密度法,对LISA中肘杆机构的上下肘杆进行了拓扑优化设计;将肘杆的应力作为约束条件,并以肘杆结构的柔度最小化和质量最小化为优化目标,构建肘杆拓扑优化的数学模型,得到了肘杆构件的最优拓扑结构。优化后的上下肘杆质量分别降低了41.89%和32.31%,且优化后的肘杆机构应力和位移均满足设计要求,为进一步设计和实验研究提供参考。
