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针对船舶建造中的锚链筒设计物理状态下的拉锚试验,以某49000 DWT成品油轮为研究对象,对其进行拉锚试验仿真,验证仿真系统的科学性和可行性.该仿真系统运用Solid Works软件实现从设计、建模到仿真的一般方法,对船舶锚以及锚链等标准件建立数据库模型,导入或者建立船艏模型,然后装配,添加约束力,进行拉锚试验仿真. 相似文献
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针对高水头混合式闸室墙结构设计领域,以柳江红花水利枢纽复线船闸闸室墙为例,结合ADINA有限元模型分析,进行锚筋计算方法的研究。通过分析,锚筋受拉过程轴向变形u与距前趾的垂向距离L_i近似成正比关系,利用u与L_i的关系,通过假定建立锚筋轴向拉力F_i与L_i及锚筋产生的力矩M_i与L_i的公式关系。为满足闸室墙检修工况下抗倾覆稳定性要求,结合锚筋提供的弯矩值Mi反推拉力值Fi,锚筋提供的拉力值均满足设计与使用要求,且越靠近顶排,锚筋发挥作用越大。通过与现有传统锚筋计算方法进行对比,该计算方法相对合理、准确,更加节省工程投资。 相似文献
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采用虚拟样机技术,利用多接触碰撞仿真分析方法代替传统木模试验对锚系运动设计进行验证。通过对拉锚速度进行多水平仿真实验,并对试验结果进行分析计算,得出了不同拉锚速度对锚系运动稳定性的影响关系,可作为大型船舶锚系设计的一个重要参考因素,值得在船舶行业推广。 相似文献
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研究抗拔锚杆荷载-位移曲线(P-S曲线)的基本特征,从岩体的性质出发,分析曲线两种类型的发展趋势。基于锚杆P-S曲线的特征,从理论上验证双曲线模型、指数模型、幂函数模型的可行性,并在Pu2处(即极限承载力12处)比较3种模型的优缺点。结合3种模型分别对现场实测数据进行拟合,进一步验证各模型的精确度和适用性。结果表明:幂函数模型拟合精度最高,适用范围广,指数模型次之,双曲线模型相对较差;抗拔锚杆P-S曲线的陡峭程度与幂函数的上凸指数有关,上凸指数介于0.75~1时曲线呈陡峭型。建议根据实际岩体性质判断曲线类型选择合适的数学模型进行描述,描述锚杆P-S曲线时优选幂函数模型。 相似文献
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依据某起锚机结构,利用国际上普遍采用的结构分析软件ANSYS,建立起锚机的有限元分析模型.依据起锚机的实际结构特点,采用了各种不同的单元类型和边界条件.通过对起锚机在各种组合载荷工况下的受力分析和强度计算,得到了起锚机各部位的应力分布图以及相应的数据,并根据结构响应的特点提出合理有效的结构加强措施和部分结构优化方案. 相似文献
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“锚杆-钢梁”组合系统是目前岩体原位测试中经常采用的一种反力施加方法,而锚杆对岩体的反力作用将会导致试验点的变形量测精度产生一定程度的偏差。通过建立锚杆对试验岩体反力作用的理论模型,导出由锚杆反力所导致
的试验点变形量的理论公式,与试验点理论变形量的公式相比对,给出了锚杆反力对试验点影响程度的计算公式。结合现场实际测试情况,根据某Ⅱ类岩体的力学参数值,分别计算出试验点的理论变形量及反力导致的变形量。结果表明:对该Ⅱ类岩体,反力导致的变形量约占理论变形量的0.035%,为提高测试结果的精确性提供了理论依据。 相似文献
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SPAR平台是目前应用较为广泛的深海石油平台形式之一,其基础形式主要有吸力锚和桩基。运用有限元分析软件Plaxis 3D Foundation,采用了Mohr-Coulomb弹塑性本构模型,选取具有代表性的吸力锚和桩基进行三维有限元分析,得到了吸力锚和桩基的极限承载力,讨论了二者承载力特性的区别及各自的适用条件。 相似文献
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The dynamic characteristics of a tunnel structure used to protect underwater power cables, the so-called A-duct, were determined for anchor collisions to provide a procedure for damage assessment and recommendations. The required physical quantities of five target anchors, including the drag coefficient, were obtained using an element-based finite-volume method and ANSYS-CFX software. The terminal velocities of the anchors were then calculated to maximize the colliding kinetic energy. For collision analysis, four parameters (anchor type, ground condition, collision velocity, and collision point) were considered, and the A-duct was modeled based on the Riedel–Hiermaier–Thoma concrete model using ANSYS-Autodyn software. Our analysis results indicated severe damage (D = 1) for most of the gauge points; the damaged area and level increased with the anchor weight. The results showed that the damage was concentrated in the collision area for stock anchors; however, for stockless anchors, damage was also evident in adjacent areas (i.e., damage propagation) due to the anchor head shape as well as the transfer mechanism provided by its reinforcing nets. Accordingly, the 2-ton stock anchor caused more damage at the gauge points near the collision location than the 2-ton stockless anchor. Second, regardless of the ground conditions and rotation angle of the anchor heads with respect to the vertical axis, the damage levels were almost identical. Fixed boundary conditions and non-rotational angle were sufficient for the model used. Third, the damaged areas became smaller when the anchor collision locations deviated from the reference gauge point (P1), i.e., the center of the A-duct. Finally, a comparison of the field-test results to equivalent numerical collision simulations indicated that the size of the predicted and experimentally observed damaged areas were in agreement within 7%. 相似文献
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刘海笑 《船舶与海洋工程学报》2012,11(4):393-401
Experimental and theoretical studies of drag embedment plate anchors recently carried out in Tianjin University are summarized in this research paper, which involve a series of important topics relevant to the study of drag anchors. The techniques for measuring the trajectory and movement direction of drag anchors in soils, the techniques for measuring the moving embedment point and reverse catenary shape of the embedded drag line, the penetration mechanism and kinematic behavior of drag anchors, the ultimate embedment depth of drag anchors, the movement direction of the anchor with an arbitrary fluke section, the reverse catenary properties of the embedded drag line, the interactional properties between drag anchor and installation line, the kinematic model of drag anchors in seabed soils, and the analytical method for predicting the anchor trajectory in soils will all be examined. The present work remarkably reduces the uncertainties in design and analysis of drag embedment plate anchors, and is beneficial to improving the application of this new type of drag anchor in offshore engineering. 相似文献
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Research on roll stabilization for ships at anchor 总被引:2,自引:0,他引:2
With the increasing importance of ocean exploitation, providing anti-rolling stability for ships at anchor has become more and more important. The lift-generation theory of traditional fin stabilizers is based on incoming flow velocity, which is not suitable for explaining lift generated at anchor. We analyzed non-steady flows, with forces on fin stabilizers generated by non-incoming flow velocity conditions, and gave a new lift-generation model. The correctness of the model was proven by comparing experimental results of fin stabilizer motion under non-incoming velocity conditions from the fluid computation software with that from the emulator of the lift-generation model. Finally, the model was used in an anti-rolling system on a ship and the reduction of roll was much better than what could be achieved by passive anti-rolling tanks. 相似文献
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