川藏公路田妥—怒江段某滑坡稳定性分析与整治

结合国道318线川藏公路田妥一怒江段K3668+700～K3668+790滑坡的基本状况,对滑坡的成因进行了分析。对K3668+715断面建立了有限元分析模型,利用有限元强度折减法,计算分析了该段滑坡在重力场和地震作用下的稳定性,计算分析求得该滑坡整治前在重力场和地震作用下的稳定安全系数分别为0.99和0.93,滑坡处于不稳定的滑动状态,应及时对该段滑坡进行整治。提出了合理的整治方案并进行了安全性评价,结果表明整治后滑坡的安全系数大于设计安全系。     

Experimental assessment of the ultimate strength of a box girder subjected to severe corrosion

The objective of this paper is to describe the experimental assessment of the ultimate strength of a severely corroded box girder subjected to a uniform bending moment resulting from four-point loading. Three box girders that could simulate the behaviour of midship sections have been deteriorated in corrosive seawater environment to simulate different levels of corrosion degradation of ageing ship structures. During the deterioration process, various parameters have been controlled and the total weight lost was registered. Corroded plate thicknesses have been measured in 212 points and a statistical analysis has been performed. The resulting corrosion wastage has been fitted by a non-linear time variant degradation model. The experimental results of the ultimate strength test of a severely corroded box girder subjected to a four-point loading have been analysed. The load-displacement and moment-curvature relationship is discussed, different failure modes are identified, and the strain gauges readings are analysed.     

Geometric stress distribution along the weld toe of the outer brace in two-planar tubular DKT-joints: Parametric study and deriving the SCF design equations

Regarding the research efforts expended so far on the calculation of stress concentration factors (SCFs) in tubular joints, two major shortcomings can be noted: (a) significant effort has been devoted to the study of SCFs in various uni-planar connections. Nevertheless, for multi-planar joints which cover the majority of practical applications, very few investigations have been reported due to the complexity and high cost involved; (b) majority of these research works focused on the study of SCFs at certain positions such as the saddle, crown toe, and crown heel, and they have ignored the hot-spot stress (HSS) at other positions along the weld toe. In the present paper, effects of dimensionless geometrical parameters on the SCF distribution along the weld toe of main (outer) braces in the axially loaded right-angle two-planar tubular DKT-joints are investigated. In order to study the multi-planar effect, SCF distribution in two-planar joints is compared with the distribution in a uni-planar joint having the same geometrical properties. A complete set of SCF database is constructed based on the two-planar DKT-joint Finite element models which are verified against experimental results and the predictions of Lloyd’s Register (LR) equations. The FE models cover a wide range of geometrical parameters. Six new SCF parametric formulae are developed through nonlinear regression analyses for the accurate and reliable fatigue design of two-planar DKT-joints under axial loads. An assessment study of these equations is conducted against the experimental data, the original FEM database and the acceptance criteria recommended by the UK Department of Energy.     

舰船结构总纵强度可靠性分析的一种新方法

提出了舰船总纵强度可靠性分析的一种新方法,探讨在短期随机海况下船体总纵强度的安全裕度的近似概率计算.通过一个例子,详细给出了短期海况下船体安全裕度的计算过程,显现出该方法在短期海况中进行船体总纵强度可靠性分析与评价的良好应用前景.     

纵向箱型梁舱段极限强度试验研究

极限强度是船体结构设计中的重要指标,试验研究是船体纵向极限强度的重要方法.纵向箱型梁是一种已运用在国外舰船上的新型结构型式.鉴于目前国内对此类结构型式的试验研究还不够充分,本文对此型式的舱段模型进行极限强度试验,观察并记录其崩溃过程.应用逐步崩溃法和非线性有限元数值方法进行模型极限强度预报.试验结果证实了极限强度理论计算方法的可靠性,其中国际船级社协会推荐的MARS2000软件的计算结果略偏保守.本试验可以为纵向箱型梁的结构设计提供参考依据.     

LNG船液舱围护系统安装平台结构强度计算分析

根据LNG液舱围护系统的安装平台设计和改造的需要,针对该平台的结构和复杂作业工况,应用MSC/PATRAN软件建立三维模型,分析平台荷载工况,计算各处最大变形位移和支座反力,还对敏感单元的屈曲强度进行了检验。研究结果为安装平台的结构强度分析提供了技术支持。     

大型绞吸挖泥船桥架结构性能研究

利用MSC.NASTRAN对三艘绞刀功率不同的绞吸挖泥船桥架结构进行结构强度比较分析,并对能够疏浚岩石的绞刀功率为4200kW的绞吸挖泥船桥架进行模态预报与响应分析,所得结果能够为以后研发具有更大绞刀切削功率、可疏浚更高强度岩石的超大型绞吸挖泥船桥架结构提供参考依据.     

基于有限元法的金枪鱼围网渔船主桅强度分析

针对金枪鱼围网渔船的实际作业工况,采用有限元方法分析了主桅及其附近甲板结构的强度,并依据CCS规范进行强度校核.结合分析结果,提出改进和优化措施,为主桅及其附近甲板结构设计提供了参考.分析表明,主桅及其附近甲板结构整体上满足强度要求;优化后的主桅结构可减重约1.2t,有助于提高整船的稳性。     

双体铝合金高速客船强度有限元分析研究

双体船具有宽敞的甲板面积和良好的稳性及操纵性等特点,在近几年备受关注,被广泛应用于军事和民用船舶领域.采用铝合金建造的船舶具有结构重量轻、耐腐蚀等优点,被主要用于观光船和快艇等小型船舶.采用直接计算法对某小型双体铝合金高速客船进行全船有限元分析,对总横强度、抗扭强度、和连接桥剪切强度进行校核,并根据计算应力结果和变形特点对其设计过程提出了几点建议.     

基于共同规范的散货船货舱口角隅疲劳强度评估

根据《散货船结构共同规范》（CSR）中疲劳强度评估的要求,使用MSC.Patran/Nastran和中国船级社开发的CSR自动加载程序,对176 000 dwt散货船货舱口角隅处进行疲劳强度分析。建立货舱口角隅处的结构有限元模型并细化网格,进行热点应力分析,根据线性疲劳累计损伤原理,进行了疲劳累计损伤计算,结果表明货舱口角隅处的疲劳强度满足规范要求。