"船舶流体力学"是船舶与海洋工程(081901)本科专业的专业基础课程之一.以面向行业需求为抓手、以夯实流体力学基础为根本,结合课堂教学实践,文章对国内已有船舶流体力学教材内容进行分析,在此基础上提炼出"船舶流体力学"教学所需解决的核心问题,并就"船舶流体力学"教材大纲编写提出初步建议.明确了"船舶流体力学"课程的定位,厘清了船舶流体力学与相关课程的关系,有助于提高"船舶流体力学"课程及后续专业核心课程的教学效果.

"船舶静力学"课程是"船舶与海洋工程(081901)"专业本科教学的基础性专业核心课程.课程目的是培养学生完成船舶在静力载荷或等效静力载荷作用下的浮性与稳性的分析能力,其内容涉及流体静力学、理论力学、微积分、数值方法等多个方面.为了建设新时代"船舶与海洋工程(081901)"专业的课程体系,作者对国内设置船舶与海洋工程类高校课程教材内容进行了对比和聚类分析,并据此确定了"船舶静力学"课程的基本共性内容.这些共性内容主要包括船体几何描述、流体静力学、船舶浮性、船舶稳性、船舶静水力资料、重物的状态改变、自由液面、进水与破舱等八个方面.在上述分析的基础之上编写的课程讲义或教材,有望取得更好的教学效果.

"船舶设计原理"是"船舶与海洋工程(081901)"本科专业教学的核心课程,该课程具有"融会贯通"的基本特征.是在汇聚船舶制图、船舶静力学、船舶推进、船体阻力、船舶操纵与摇摆、船舶强度与结构设计、船舶建造工艺等诸多专门知识的基础上,形成的一门综合应用知识的课程,是船舶整个技术历程包括设计、建造、营运和拆解中贯穿实践知识的课程.本文在分析国内已有教材内容的基础上,提出了"船舶设计原理"课程所涉及的基本共性内容及其相应的知识点,形成"船舶设计原理"课程教学的基本知识架构.

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 three-channel optical waveform synthesizer is demonstrated for generating intense continuum soft-x-ray pulses by HHG. With the full stabilization of temporal delays, relative phases, and CEPs, precision control of shot-to-shot reproducible synthesized waveforms is achieved. © 2019 The Author(s)

The determination of process paths and parameters according to the strain field that required to forming a double-curved desired shape is an important work during the process design of line-heating and rolling forming in thepro-cess design of line heating and rolling forming. Therefore, the precision of Calculated strain field will affect the accuracy of process paths and parameters. This paper presents a method to calculate the strain filed required to develop a desired shape to a planar shape depend on mechanic theory. Firstly, nodal displacements is applied to the flat plate via elastic-plastic finite element analysis. Owing to the spring back, the shape calculated by elastic-plastic finite element analysis is different between the required shape, then the deviation between calculated shape and required shape is calculated, and reverse deformation is added to nodal displacements, this process continues until the deviation can meet the requirement of precision to terminate the loop. Finally, the obtained strain field is applied to flat model as initial strain to verify the accuracy of this method, and results shows that it has very high calculation precision, this method provide the foundation of the determination of process paths and parameters.

Elastic FE simulation with inherent deformation and interface element is an ideal and practical computational approach for predicting welding distortion in production of thin plate structures. In this study, recent researches on inherent deformation theory and welding induced buckling investigation of ship panel were sequentially introduced. Taking bead-on-plate welding as research objective (plate with 2.28 mm in thickness), integration approach with inherent strain was proposed to accurately and conveniently evaluate magnitude of inherent deformation. Also, average temperature to clarify the mechanism of influential effect of plate width on magnitude of inherent deformation was presented and examined. With the mechanism investigation of welding induced buckling by elastic FE analysis using inherent deformation, an application for predicting and mitigating the welding induced buckling in fabrication of ship panel with thin plates by employing different welding procedure patterns was carried out. Examined intermittent zigzag welding procedure is effective to reduce the magnitude of in-plane inherent shrinkages and control the possible welding induced buckling. (C) 2016 Elsevier Ltd. All rights reserved.

In process of forming curved plate,determining in-plane deformation and bending deformation quantitatively for a given target surface is required,so as to obtain proper molding way.In order to determine distribution of strain,it is necessary to explore various factors affecting the distribution of strain.For this purpose,relation between various parameters,such as initial curvature,thickness of plate and target curvature,and strain distribution is analyzed with finite element method in this paper.That will provide data support to the creation of database of the relationship between the strain and the target surface shape.The study results show that initial curvature significantly affects the bending strain but little affects the in-plane strain;in-plane strain doesn’t vary with the change of thickness and bending strain increases linearly with the increase of thickness;bending strain and in-plane increases linearly with the increase of the target curvatures.

In process of forming curved plate,determining in-plane deformation and bending deformation quantitatively for a given target surface is required,so as to obtain proper molding way.In order to determine distribution of strain,it is necessary to explore various factors affecting the distribution of strain.For this purpose,relation between various parameters,such as initial curvature,thickness of plate and target curvature,and strain distribution is analyzed with finite element method in this paper.That will provide data support to the creation of database of the relationship between the strain and the target surface shape.The study results show that initial curvature significantly affects the bending strain but little affects the in-plane strain;in-plane strain doesn’t vary with the change of thickness and bending strain increases linearly with the increase of thickness;bending strain and in-plane increases linearly with the increase of the target curvatures.

The effect of boundary conditions on welding residual stress was discussed in this paper.Welding residual stress of high-strength steel for marine thick plate was simulated with the method of 3D thermo-elastic-plastic finite element.Effectiveness of the method was verified through test measurement.Then a study of the effect of boundary conditions on residual stress was developed.The results indicate that constraint locations and surface convection conditions have an impact on residual stress to a certain extent and structure restraint modes have a greater impact.

The effect of boundary conditions on welding residual stress was discussed in this paper.Welding residual stress of high-strength steel for marine thick plate was simulated with the method of 3D thermo-elastic-plastic finite element.Effectiveness of the method was verified through test measurement.Then a study of the effect of boundary conditions on residual stress was developed.The results indicate that constraint locations and surface convection conditions have an impact on residual stress to a certain extent and structure restraint modes have a greater impact.

It is necessary to do a thorough research on the ultimate strength of cylindrical shells under the condition of crack growth to estimate and predict accurately bearing capacity of naval architecture and offshore structures with fatigue crack.In this paper,the effect of various parameters on the ultimate strength and its parameter sensitivity are analyzed through systematical calculation with existing theoretical analytic solutions based on the elastic-plastic crack and crack growth.The parameters include initial crack length,diameter thickness ratio,critical CTOD,critical CTOA,yield stress and Young's modulus.Besides,dimensionless parameters including loss coefficient of ultimate strength κ,redundancy coefficient of strength λ and residual length of crack extension ξ are introduced to assess the variation of carrying capacity of structure caused by crack growth.This paper provides a basic work for the assessment of effect of crack damage on the ultimate strength of the whole structure.

The general plan of the ship painting management system was designed and the subsystems of painting management and painting production were realized.Considering the aims of the ship panting management system should achieve,the Oracle DBMS was applied to create a B/S framework of the system by using the Servlet/JSP as application layer and the browser as interface layer.The painting management subsystem and painting production design subsystem were encoded in Java while the CVMAC in CADDS5 environment was used to exploit the area statistics program to supply the painting area data for the painting design.

Reference line coincides with the water line and extends throughout the whole length of ship hull, while offset points are laid along the rib-lines. Such an approach of developing the curved surfaces of ship hull along two mutually perpendicular directions is proven to be better than the former way of flattening the surfaces merely along the rib-lines. The new process is implemented and validated on the platform of MDT software, showing that both the speed and quality of laying tiles on the whole ship hull are remarkably improved.

Cylindrical shells are a sort of main structural members in naval architecture and offshore structures.Due to heavy cyclic wave loads,fatigue cracks as a kind of common and dangerous dam- age to safety may occur in the construction.Therefore the research on the cracked cylindrical shell is always a hot subject.In general,some material with sufficient ductility is used for these structures, then it is possible that there is a large plastic area around the crack front before the crack growths. Thus it is necessary that elastic-plastic analysis of fracture is applied in this case. On the other hand,the evolution of the cracked cylindrical members under loading is closely related to the struc- tural system,which contains the members.Thus elastic-plastic analysis of the structural system con- taining the cracked members as a whole is required.However such a calculation by means of the or- dinary finite element method is a task of enormous efforts due to the crack existence and nonlineari- ty.Therefore it is necessary to develop a new structural element considering influences of the elastic- plastic crack with the least unknowns.In this paper,incremental derivation is performed to Sanders' elastic-plastic analytical solutions for circumferential through-cracked cylindrical shells.The explicit relationships between nodal force and displacement are obtained.The relevant element stiffness e- quation in tangential incremental form is established.The new element provides the ability to predict the elastic-plastic behavior of structural system with cracks on a necessary theoretical base.