排序方式: 共有78条查询结果,搜索用时 15 毫秒
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以波纹夹芯杂交夹层板(Hybrid Sandwich Plate with Corrugated-Cores,HSP)为研究对象,建立气-液-固三相数值模型,对结构在不同撞水速度下(1~10 m/s)动力响应特性进行数值计算分析.首先将其与相同质量的无填充轻质波纹夹芯夹层板(Light Weight Corrugated-Core Sandwich Plates,LWCCSP)在入水砰击下的非线性力学行为进行对比,分析探讨2种结构的能量吸收特点以及砰击压力和变形的分布规律,同时研究波纹夹芯杂交夹层板主要设计参数对其抗砰击性能的影响.分析结果表明,波纹夹芯杂交夹层板较同质量的无填充轻质波纹夹芯夹层板具有更好的抗砰击性能;在一定范围内,增加触水面板厚度及芯层厚度对提升波纹夹芯杂交夹层板的抗砰击性能有积极作用,且增加芯层厚度效果更为显著. 相似文献
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基于全船建模的航速对船首外飘砰击影响研究 总被引:1,自引:1,他引:0
建立二维楔形体入水模型,验证入水砰击仿真方法可靠性,对集装箱船体进行全船体建模,导入船体运动参数,增加船体的纵摇运动,采用一般耦合算法(General coupling),流体域用Euler单元模拟,船体设为刚体,划分为Lagrange有限元网格,对船体进行入水仿真.对比不同工况下的结果表明:全船模拟时船型纵向斜升角会发生变化,导致航速对船首入水砰击压力的影响较大,随着航速的增加,入水砰击压力变大,同时航速还会使砰击压力峰值位置发生变化. 相似文献
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影响高速三体船连接桥砰击压力峰值因素研究 总被引:2,自引:0,他引:2
利用LS-DYNA仿真软件建立高速三体船连接桥结构二维有限元模型,计算其入水砰击问题。计算中考虑高速三体船的空气层、结构质量、连接桥宽度和主船体的舭升高角度因素对连接桥砰击压力峰值影响。通过分析,得出各个因素对高速三体船连接桥砰击压力峰值的影响规律。 相似文献
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基于流-固耦合有限元法,对工程中经常出现的水平方向高速运动物体砰击水面后的动特性建立了三维砰击模型,并开展了相应的仿真、分析研究,得出了高速运动物体砰击水面后的运动轨迹及其动特性.研究成果对工程中诸如民航飞机水上迫降、空投物体的入水特性分析及高速航行的船舶引擎突然熄火后的动特性研究等工作具有十分重要的现实指导意义. 相似文献
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船体结构遭受的波浪砰击载荷是一种强非线性的流体与结构之间的相互作用。砰击将导致船体主要按其两节点湿谐振频率发生振动,这种船体梁的总振动即为颤振。它往往引起船体结构的极限强度问题和疲劳损伤问题,这两种问题在船舶结构设计领域不可回避。从理论研究方面对船舶的砰击总体载荷进行综述,分析二维理论和三维理论在预报船体结构砰击总体载荷方面的优缺点。分析表明:虽然二维理论在该领域的应用已超过50年,但理论中基本假设和数学模型的局限性制约了其在肥大型船、多体船和海洋平台等领域的广泛应用;三维理论能突破二维理论的基本假设和数学模型的局限性,能在更加广泛的工程领域内得到应用。考虑外飘等非线性影响的三维时域水弹性理论能更加精确地预报砰击载荷,是船体结构砰击总体载荷理论研究的重要发展方向之一。
相似文献49.
Numerical uncertainty due to discretization on the Arbitrary Lagrangian-Eulerian (ALE) Finite Element method is investigated in the study. The paper quantifies uncertainty using two ITTC recommended methods, and also applies a constant Courant-Friedrichs-Lewy (CFL) number based discretization approach, instead of performing the independent grid and time-based discretization recommended by ITTC. As a case study, water entry of a flat bottom rigid and flexible plate is simulated considering various entry velocities. The total slamming loads and structural responses on both the rigid and elastic bottom plates are predicted and validated against available experimental data. Results indicate that numerical errors due to discretization differ in the various parameters and from case to case. They do affect the analysis of slamming loads and associated structural responses, and the hydroelasticity analysis as well. The hydroelasticity effects on the slamming force generally increase as the entry velocity increases, however, the quantitative results differ much for models with different grids. For example, when the hydroelasticity effect is estimated using the finer model, the deviation of the total slamming force on the elastic plate relative to the one on the rigid body are 56%, 57%, and 63% respectively for the three constant entry velocities, whereas the estimations are −27%, −4% and 3% with the coarser model. The study concludes that the uncertainty due to discretization in ALE is not just case-specific, but also parameter specific. The uncertainty quantification procedures with a constant CFL number based refinement are recommended to investigate the uncertainty comparing to the individual grid and time step study, in particular for the ALE solution where the time step is adjusted automatically as the grid changes. Thus, consideration should be given to updating the ITTC guidelines to incorporate the constant CFL based discretization approach. 相似文献
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[目的]为研究M型快艇典型截面结构入水过程中受到的水动力载荷,[方法]基于光滑粒子动力学(SPH)液-气两相流算法,模拟平板和弓形模型的入水过程,以验证所用算法的精确性。在此基础上,模拟M型快艇典型截面结构的入水过程,并与相关文献的试验结果进行比较。[结果]结果显示:两种结构入水过程的仿真结果与试验结果吻合较好。M型快艇入水过程中存在二次砰击现象,即在主船体斜升角较大时会导致第1次砰击载荷较小,若斜升角过大时第2次砰击过程中结构则受到的砰击载荷会显着增加。[结论]研究结果表明,SPH两相流算法可以很好地模拟M型快艇入水过程,斜升角的设计大小应适当。 相似文献