复合电源能量匹配与多目标模糊控制策略研究

分析了复合电源纯电动汽车的电源结构和工作模式,依据纯电动汽车基本性能指标对复合电源进行了能量匹配,制定了能源安全约束,并基于此制定了多目标模糊控制策略。仿真结果表明,所提出的控制策略能够充分发挥超级电容的优势,可提升纯电动汽车续驶里程、合理分配复合电源功率及减小车速误差。     

A380-800飞机荷载作用下复合道面的结构响应分析

为了分析机场复合道面结构在新一代大型飞机多轮荷载作用下的力学响应规律,文章以A380-800飞机为例,应用大型通用有限元程序ABAQUS建立了复合道面结构三维有限元模型,分析了多轮荷载不同组合方式作用下道面结构的力学响应。通过计算不同布载形式下道面结构的疲劳寿命,并结合应力的分布规律,得出结论:复合道面在多轮荷载作用下产生空间叠加效应;A380-800可采用3轴双轮6轮组作为道面结构设计时的最不利荷载组合;当考虑空间叠加效应时,15 m×15 m的模型尺寸是合理的。     

Extreme response based reliability analysis of composite risers for applications in deepwater

As current oil reserves start to deplete, companies are looking to exploit deeper deposits. At these greater depths composite risers, with their high strength-to-weight ratio, reduce the effective tensions and bending moments compared to steel risers. However, there is still limited research into their behaviour, with one key missing element being a comparison with traditional riser designs which accounts for variances in material properties and wave loads. This paper therefore conducts a strength-based reliability analysis of composite catenary risers operating between 1,500 m and 4,000 m. A static global catenary model is combined with Classical Laminate Theory to determine the extreme response and its performance is verified against FEA. This response is evaluated with the Tsai-Wu failure criterion to determine first-ply failure. The effect of laminate moisture absorption on the long-term reliability of submerged composite-based risers is also investigated as it can cause a significant reduction in the strength of composite risers. The reliability analysis is conducted using the Monte Carlo Method, revealing that the composite risers perform well at 4000 m. The degradation in performance from moisture absorption becomes increasingly important at greater depths and needs further investigation for these applications.     

微型桩在岩溶地区桥梁基础加固的应用

在贵州大兴至思南高速公路建设工程中采用了一种安全可靠、经济合理的新型桥梁基础加固方案。对该方案加固的特点、受力进行了分析,并简要介绍了其施工过程,为类似地区的桥梁基础加固提供参考。     

CFG桩复合地基在公路路堤荷载作用下变形计算分析

详细介绍了CFG桩复合地基在公路路堤荷载作用下的变形模式和计算方法,并根据某高速公路试验路段的实测数据进行CFG桩复合地基变形计算,通过对计算值和实际沉降变形量进行对比,对CFG桩复合地基在公路路堤荷载作用变形计算进行分析。     

最小弯曲能量原理在确定拱梁组合体系吊杆成桥张拉力中的研究

基于最小弯曲能量原理,推导了拱梁组合体系吊杆成桥张拉力的索力计算方程,并考虑构件拉压力与索力影响矩阵,得出了相应的最优索力矩阵方程。     

A simulation evaluation of the maximum approximate composite marginal likelihood (MACML) estimator for mixed multinomial probit models

This paper evaluates the ability of the maximum approximate composite marginal likelihood (MACML) estimation approach to recover parameters from finite samples in mixed cross-sectional and panel multinomial probit models. Comparisons with the maximum simulated likelihood (MSL) estimation approach are also undertaken. The results indicate that the MACML approach recovers parameters much more accurately than the MSL approach in all model structures and covariance specifications. The MACML inference approach also estimates the parameters efficiently, with the asymptotic standard errors being, in general, only a small proportion of the true values. As importantly, the MACML inference approach takes only a very small fraction of the time needed for MSL estimation. In particular, the results suggest that, for the case of five random coefficients, the MACML approach is about 50 times faster than the MSL for the cross-sectional random coefficients case, about 15 times faster than the MSL for the panel inter-individual random coefficients case, and about 350 times or more faster than the MSL for the panel intra- and inter-individual random coefficients case. As the number of alternatives in the unordered-response model increases, one can expect even higher computational efficiency factors for the MACML over the MSL approach. Further, as should be evident in the panel intra- and inter-individual random coefficients case, the MSL is all but practically infeasible when the mixing structure leads to an explosion in the dimensionality of integration in the likelihood function, but these situations are handled with ease in the MACML approach. It is hoped that the MACML procedure will spawn empirical research into rich model specifications within the context of unordered multinomial choice modeling, including autoregressive random coefficients, dynamics in coefficients, space-time effects, and spatial/social interactions.     

汽车复合材料板弹簧的有限元分析及性能测试

利用ABAQUS有限元软件,对设计的某型号汽车复合材料板弹簧进行了有限元分析,计算了复合材料板弹簧的刚度系数和最大承载力,并对采用模压工艺制备的复合材料板弹簧样件进行了性能测试.计算与试验对比表明,计算结果与测试结果吻合较好;设计的复合材料板弹簧的主要性能指标达到设计要求,且复合材料板弹簧可比钢板弹簧减重约63％.     

微型客车顶盖冲压成型用复合材料模具及制造工艺

介绍了微型客车顶盖冲压成型用复合材料模具的结构及其制造工艺。该模具的凸、凹模均用复全材料制造，模架、围板、压力圈、镶条等用普通钢材制造。它通过曲在曲线线型压边圈及其上的阻力筋，在压力拉延的同时，压出流水槽，只用一道工谲即将整体式顶盖一次拉延成型。