研究了甲板结构在圆管形坠落物冲击下的变形及损伤特性.首先运用试验与有限元方法,研究甲板板格在圆冲头冲击下的响应特性;然后进行加强型结构抗冲击有限元模拟.结果表明,因冲头尺寸较小,原甲板结构较易产生局部损伤,而纵向强筋可显著减轻结构损伤程度.在工程船的甲板结构设计中,宜尽量增加加强筋数量、减小筋间距,以避免甲板结构受坠落物冲击产生过早损伤.

采用有限元数值计算方法对嵌入式带缆桩典型甲板加强结构尺寸进行计算分析,对比不同连接型式、不同过渡距离等设计方案,计算结果表明,带缆桩加强T型材的腹板高度、面板规格对结构强度影响显著,甲板厚度、带缆桩壁厚等对结构强度影响较小;T型材与带缆桩牢固连接方案较优.

ObjectivesIn order to study the bearing characteristics and failure modes of a cracked pipe wrapped in carbon fiber-reinforced polymer (CFRP), a three-point bending test is carried out on a cracked aluminum alloy pipe strengthened with CFRP using epoxy resin. MethodsThe reparative effects are evaluated by comparing the load-displacement curves before and after the repair, and the effects of crack length and repair width and thickness on the bearing capacity and failure mode of the samples are further discussed. A three-point bending simulation model of the cracked pipe repaired by CFRP is established to simulate the failure of the adhesive layer and carbon fiber cloth. The experimental results are compared with the simulation results. ResultsThe test and simulation results show that the use of a three-layer carbon fiber cloth can effectively inhibit crack propagation. With the increase in the number and length of reinforcement layers, the ultimate bearing capacity of the sample increases. The maximum bearing capacity of samples repaired with four-layer carbon fiber cloth greatly exceeds that of uncracked pipes, but the ductility and shear bearing capacity of the pipes are reduced. For the same repair layer, the ultimate bearing capacity after repair shows a greater downward trend with the increase in crack length. ConclusionsThe results of this study have certain guidance and reference significance for cracked pipe reinforcement in engineering.

[目的]给出一种快速准确地估算含上层建筑船型总纵弯曲应力的方法.[方法]在前人研究的基础上,以某典型一体化上层建筑船型为对象,采用有限元数值仿真计算方法,对多种不同上层建筑的船舶进行有限元建模计算,结合3种定义方法计算上层建筑有效度,与采用常用的上层建筑有效度简化计算公式(英国劳氏规范经验公式、俄罗斯公式1、俄罗斯公式2)的结果进行对比.[结果]结果表明,这些简化计算公式在上层建筑中部区域附近的有效度预报值差别不大,与有限元值较为接近,但在远离中部区域时误差较大.而对不同长度、高度、厚度的有效度计算结果的对比表明,俄罗斯公式1计算得到的有效度与第3种定义方法的结果吻合度高,其与该定义方法结合后预报的应力值与有限元计算结果误差小.[结论]所提方法可作为一体化上层建筑船型船体梁弯曲应力的预报方法之一.

[Objectives] The result of ship collision is often catastrophic,especially a marine ecological disaster caused by the collision or stranding of double-hull oil tanker is difficult to recover from for many years. In order to assess the crashworthiness of double-hull structure,the test and simulation study on the damage characteristics of double-hull ship structures subjected to head-on collision on by a wedge indenter were conducted.[Methods] First, quasi-static indentation experiment is performed for double-hull structure model. Then the finite-element software LS-DYNA is used to perform numerical simulation of the double-hull structure test model.[Results] The study results indicate the test matches well with the numerical simulation in terms of collision load response and deformation modes. There is great difference between the deformation and damage modes of the outer plate and inner plate of the double hull. Due to the plastic deformation in web girder between the outer and inner plates,the fracture initiation in outer plate was delayed.[Conclusions] The results in this research could be used to assess the damage characteristics of boardside structure or ship bottom structure during under collision or stranding.

介绍了船舶吊舱式推进器的性能优点,吊舱推进器支撑结构设计校核的难点,给出吊舱支撑结构设计和校核的指导思路.结合一艘4000t级船舶,提出吊舱支撑结构设计的具体实施方法,并采用有限元分析方法,对设计的吊舱支撑结构结构进行校核,验证设计的合理性,为同类吊舱支撑结构的设计、校核及进一步优化提供指导.

泡沫填充波纹夹层板结构具备较高的极限承载能力及较好的冲击吸能能力.基于ABAQUS通用平台建立了泡沫填充波纹夹层板结构平面压缩特性的数值模拟方法,对无填充、聚氨酯泡沫填充及泡沫铝填充的波纹夹层板结构进行平面压缩的系列化有限元数值模拟.计算结果表明,泡沫填充对波纹板结构有较好的增强作用,可提高结构的极限承载能力及能量吸收能量,芯层愈弱效果愈好.高强度泡沫铝填充材料可使腹板的屈曲模式由一阶向高阶转变,从而大幅提高极限承载能力及吸能能力.研究成果可为新型混杂波纹夹层板的设计应用提供参考建议.

A corrugated core sandwich structures were fabricated with carbon fiber reinforced polymer(CFRP)face sheets and aluminum alloy cores.Experimental study was conducted on the impact damage and residual flexural strength.The results showed that the residual flexural strength of corrugated core sandwich structures is affected by damage resulted by low -velocity im-pact.There is a slight reduction as further increasing of the impact energy.The residual flexural strength is affected by the impact location.

为研究具有大开口甲板板架结构的稳定性问题,本文设计了含大开口结构的甲板板架模型,开展了其轴向受压稳定性实验,并采用非线性有限元软件Abaqus对该模型的屈曲破坏过程进行数值仿真计算,试验结果与数值仿真结果吻合较好.在此基础上,根据甲板结构屈曲失效的诱因,设计5种改进设计方案,并使用经试验验证的有限元仿真计算方法对各种改进方案进行分析,选出最佳方案.本文工作为船舶甲板结构稳定性设计提供了一定的参考依据.

本文设计了舷侧不连续的双层板架结构模型,开展了该结构轴向受压稳定性试验,并采用非线性有限元软件Abaqus对其屈曲失效过程进行了数值仿真计算,分析了结构屈曲失效的诱因及过程.在此基础上,为提高该结构轴向受压稳定性,本文设计了4组改进设计方案,并使用经试验验证的有限元建模计算方法对这4种方案进行分析,选出最佳方案.本文的改进设计方法为此类结构的稳定性设计提供了参考依据.

本文开展了含大开口结构的双层板架模型轴向受压稳定性实验,采用非线性有限元软件ABAQUS,建立了甲板大开口双层板架模型,开展了该模型在轴向压缩载荷作用下的屈曲失效过程的数值计算分析,数值计算结果和试验吻合较好.在此基础上,根据甲板结构屈曲失效诱因,将双层板架模型简化为单层板架局部模型,并分析了简化模型在轴向载荷作用下的屈曲破坏路径与极限承载能力.结果表明,简化后的加筋板模型能有效模拟双层板架模型的失效模式,为大开口甲板板架稳定性分析提供了新思路.

[Objectives]In order to efficiently reduce the bending stress of a grillages in a rectangular cabin under internal pressure,mathematical models for the optimization of the vertical positions of platforms and size and layout of pillars are proposed respectively. [Methods] The vertical positions of the two internal platforms are taken as the design variables,the maximum bending stress of the transverse and longitudinal bulkhead structure is minimized,and the optimal positions of the internal platforms are obtained via a genetic algorithm. The optimization results show that the best positioning of platforms is close to the vertical uniform distribution. A stepwise optimal pillar design method is proposed. First,the maximum bending stress of the top deck structure is minimized by taking the positions of pillars with the same stiffness as the design variables. Through the repeated use of the model,optimal layout schemes under different numbers of pillars can be obtained in succession. The number and layout of the pillars are then selected according to the stress constraints. To further reduce the maximum bending stress of the top deck structure under a given number and layout of pillars,a mathematical model for the optimal variable stiffness of pillars is proposed. In this study,pillar cross-section size is treated as a design variable,the weight of the pillars in the previous round of optimization design is treated as the constraint,and the maximum bending stress of the top deck structure is minimized. [Results] The optimization results show that the pillars in the central zone are large than those in other regions. By using the proposed optimal design models,the maximum bending stress of the transverse and longitudinal bulkheads and top deck is reduced by 28.3% ,25.7% and 13.9%respectively.[Conclusions] Theproposedmethodcanprovidereferencepointsforcomparablestructuraldesign.

Applying the flat fore hull structure to the mid-bow of Wave Piercing Catamaran (WPC) can provide reference object for the boat driver and protect the demi-hulls on the conditions of shipping and docking.In this paper the flat fore hull form of ordinary catamaran is used for WPC,coming into a hybrid WPC line plan.After optimizing of the mid-bow of WPC,model seakeeping test,structural process designing and strength analyzsis,this practical application of flat fore hull structure to the mid-bow of WPC is found to be feasible.It can be used as reference for the design of similar WPC.

The cross-structures of wave piercing catamaran (WPC) are subjected to large transverse bending moment and torsion moment under transverse and oblique waves. Its strength is critical to its safety. Based on the finite element analysis (FEA),direct computation was performed on a full FEA model of WPC to obtain its transverse and torsion strength,and then to check its global strength. The preliminary study was conducted on the effects of the top structures on the global transverse strength. Through analyzing the computing results,the stress distributions were obtained and could be used as ref-erences in the optimal design of WPC.