汽车动力总成弯曲振动应力响应及其激励灵敏度分析

本文利用文献（５）建立的汽车动力总成弯曲有限元分析模型，计算分析离合器壳的动应力响应，并考察了动应力关于不平衡质量位置的灵敏度，对计算分析进行了实验验证。     

Variational principles in water-wave problems (wave radiation conditions and their variational treatment)

To discuss water-wave problems in unlimited waters, it is important to know what type of wave radiation condition should be placed on a virtual surface corresponding to infinity. For this kind of problem, the Sommerfeld radiation condition is well known. In this article, the condition is extended to treat a case with an incident wave. Furthermore, a more general wave radiation condition is introduced from a different point of view. The above-mentioned wave radiation conditions are introduced into the variational principles of the Kelvin, Hellinnger–Reissner, and Dirichlet type. The Dirichlet-type variational principles are then used in numerical calculations for bending waves in a bar, and the effectiveness of the wave radiation conditions and the variational principles is shown. The numerical results for one-dimensional water-wave problems are then given. As expected, the region required for the numerical solution is reduced drastically compared with that required by the Sommerfeld-type formulation. Furthermore, the amplitude of the diverging wave is obtained in the process of reaching the variational solution. Finally, two-dimensional water-wave problems are briefly discussed. Received: August 9, 2001 / Accepted: September 17, 2001     

CWELD焊点类型有限元结构刚度分析

针对在白车身等复杂的焊接结构进行有限元分析过程中,不同焊点的模拟方法对结构的弯曲刚度和扭转刚度影响较大的问题,文章对CWELD焊点进行研究,以RBE2刚性单元为参照,得出CWELD焊点对弯曲和扭转刚度的影响,为焊点的有限元建模方法积累经验。     

板裂围岩结构弯曲失稳分析

文章分析了板裂结构地质背景及板裂介质岩体特征,研究了板裂围岩破坏模式及力学机理,并结合工程实例,利用随机有限元模型对板裂结构屈曲破坏进行分析。     

大断面水下盾构隧道管片接头抗弯刚度及其对管片内力影响研究

以大断面水下铁路盾构隧道-狮子洋隧道工程为研究对象,运用有限元数值分析方法,并结合管片接头原型抗弯试验,研究环向管片接头抗弯刚度,并运用梁-弹簧模型进行接头抗弯刚度对整环管片结构内力影响的研究.结果表明:该隧道管片接头抗弯刚度的取值范围为50～700MN·m·rad-1,在相同轴力条件下,接头抗弯刚度会随接头弯矩的增加降低1个数量级左右;在相同接头弯矩条件下,接头抗弯刚度随轴力的增加而增大;接头抗弯刚度对管片轴力分布的影响微弱,对管片弯矩的影响显著;随接头抗弯刚度的增大,整环管片的弯矩分布趋于均匀;在抗弯刚度取值范围内,极值弯矩相差最大达80％左右,极值轴力最大减小5％左右,变形最大减小20％左右;基于接头抗弯刚度-弯矩-轴力的非线性关系改进的梁-弹簧模型,更能体现接头对整环管片受力的影响,也更适用于大断面盾构隧道管片内力的计算.     

不同纵筋率高强钢筋RPC梁抗剪承载力及剪切延性试验研究

为研究纵筋率对高强钢筋活性粉末混凝土梁剪切性能的影响,进行集中荷载下5根RPC梁的受剪试验,分析纵筋率对梁的斜裂缝宽度、剪切延性及抗剪承载力的影响。结果表明:试验梁的抗剪承载力随着纵筋率的提高而提高,而剪切延性随着纵筋率的提高而降低;采用高强钢筋的活性粉末混凝土梁,正常使用极限状态下斜裂缝最大宽度不超过0.3 mm。建立考虑纵筋作用的高强钢筋活性粉末混凝土梁抗剪承载力计算的经验公式,利用经验公式对搜集的27根梁进行计算,吻合较好且变异系数小。该公式具有一定的参考意义,可为高强钢筋活性粉末混凝土梁抗剪承载力的研究提供参考。     

双壳船内外底结构强度探讨

文章利用“船舶结构力学”原理,对双壳船中的双层底结构进行受力分析,同时结合现行规范,提出较为切合实际的强度计算公式。     

At-sea towing of a Mega-Float unit

A huge floating offshore platform (359m long, 60m wide, and 3m deep) was towed into the Pacific Ocean for a validation experiment for a floating airport. Full-scale measurements of towline tension and the bending strain on the upper-deck were made during towing. The measured bending moment agreed well with numerical calculation without taking the draught and towing speed into consideration.     

不同掺量硅藻土改性沥青胶浆性能研究

不同掺量硅藻土改性沥青的三大指标对比试验结果表明，掺加硅藻土对于沥青的感温性、高温稳定性有所改善，改善效果随掺量增加而提高；不同掺量的硅藻土改性沥青PI值比基质沥青明显有增大趋势，当量软化点T800较基质有所升高，当量脆点T1,2降低，并且都在11％-12％处出现峰值，表明掺量在11％～12％之间温度敏感性较低。     

层内混杂纤维布约束混凝土柱轴压性能试验研究

试验采用三种纤维(芳纶纤维、聚脂纤维和尼龙纤维)混杂而成的IHFRP布.通过IHFRP布约束混凝土圆柱体、棱柱体的轴压试验,研究了其破坏形态、应力一应变全曲线、峰值应力、极限应变、延性性能.试验结果表明:IHFRP显著提高了柱的承载力,对于相同层数纤维布约束试件随着混杂纤维布中芳纶纤维含量的增加,承载力增长越显著;IH...