水稳混合料最大干密度及最佳含水量的理论求算

文章通过对最大水泥填充集料空隙质量的测定,以及与此相关的变化的水泥填充集料空隙质量的计算,详细推证了水稳混合料最大干密度ρ′dmax及最佳含水量ω′0的理论公式,并结合实例数据对比分析了推证公式的准确性,同时阐述了采用推证公式应注意的事项。     

山区公路路基稳定性的研究

阐述了山区路基的结构形式。影响路基稳定性的成因,并从施工和防护两个方面论述了保证路基稳定性的措施和方法。     

一种用μ分析设计的舵减摇鲁棒控制器

船舶模型不确定性严重影响着舵减摇的效果。本文用μ分析方法设计了一种Ｈ∞控制器来解决结构化模型不确定性的问题。用船舶线性模型和非线性模型模拟海上航行条件的计算仿真表明μ分析控制器具有良好的鲁棒特性。     

基于降低悬挂式单轨车辆侧滚的结构参数优化研究

根据悬挂式单轨车辆的结构特点,通过多体动力学软件ADAMS建立悬挂式单轨车辆动力学模型。以车辆走行轮、导向轮、吊架、空气弹簧、中心销、横向拉杆、横向减振器等结构参数作为设计变量,结合多目标优化软件Mode FRONTIER和单因素敏感性分析方法,探索了影响悬挂式单轨车辆侧滚的因素,并甄别出影响悬挂式单轨车辆侧滚的主要因素;针对影响车辆侧滚的主要因素,确立将车辆具有良好的曲线通过性和运行稳定性作为约束条件,建立了以车辆侧滚为目标的优化数学模型,采用第二代非劣排序遗传算法为优化方法,进行了以车辆侧滚最优为目的的优化研究。优化结果表明:在满足给定的约束条件下,当单轨车辆各参数达到最优解时,车辆侧滚角减小了6.3%～11.4%。     

冷弯成型局部大变形测试装置的设计与研究

冷弯成型变形复杂，事先难以预测其变形效果。根据冷弯成型的特点和变形规律设计出基于万能实验机上的局部大变形测试装置，并应用此装置对冷弯成型过程进行回弹分析，为冷弯成型理论分析和使用ANSYS／LS-DYNA对冷弯成型分析提供科学依据。     

热循环对Fe—23Mn和Fe—28Mn—4Si合金马氏体相变和组织结构的影响

Ｆｅ－２３Ｍｎ合金和Ｆｅ－２８Ｍｎ－４Ｓｉ合金的马氏体相变在热循环中行为截然相反，Ｆｅ－２３Ｍｎ合金奥氏体经热循环后产生稳定化，随着热循环次数增加，ε马氏体数量减少直至消失，得到单相奥氏体组织，但质变循环稳定化的奥氏体在室温时效过程中发生等温γ→ε相变，Ｆｅ－２８Ｍｎ－４Ｓｉ合金奥氏体经热循环不产生稳定化。ε马氏体数量不是减少，而是明显增多，Ｆｅ－２８Ｍｎ－４Ｓｉ合金γ→ε相变具有组织遗传特征，而     

Real-time estimation of the road bank and grade angles with unknown input observers

This paper proposes an approach for the estimation of the road angles independent from the road friction conditions. The method employs unknown input observers on the roll and pitch dynamics of the vehicle. The correlation between the road angle rates and the pitch/roll rates of the vehicle is also investigated to increase the accuracy. Dynamic fault thresholds are implemented in the algorithm to ensure reliable estimation of the vehicle body and road angles. Performance of the proposed approach in reliable estimation of the road angles is experimentally demonstrated through vehicle road tests. Road test experiments include various driving scenarios on different road conditions to thoroughly validate the proposed approach.     

Enhancing roll stability of heavy vehicle by LQR active anti-roll bar control using electronic servo-valve hydraulic actuators

Rollover of heavy vehicle is an important road safety problem world-wide. Although rollovers are relatively rare events, they are usually deadly accidents when they occur. The roll stability loss is the main cause of rollover accidents in which heavy vehicles are involved. In order to improve the roll stability, most of modern heavy vehicles are equipped with passive anti-roll bars to reduce roll motion during cornering or riding on uneven roads. However these may be not sufficient to overcome critical situations. This paper introduces the active anti-roll bars made of four electronic servo-valve hydraulic actuators, which are modelled and integrated in a yaw-roll model of a single unit heavy vehicle. The control signal is the current entering the electronic servo-valve and the output is the force generated by the hydraulic actuator. The active control design is achieved solving a linear optimal control problem based on the linear quadratic regulator (LQR) approach. A comparison of several LQR controllers is provided to allow for tackling the considered multi-objective problems. Simulation results in frequency and time domains show that the use of two active anti-roll bars (front and rear axles) drastically improves the roll stability of the single unit heavy vehicle compared with the passive anti-roll bar.     

Contour line of load transfer ratio for vehicle rollover prediction

For vehicle rollover control systems, an accurate and predictive rollover index is necessary for a precise rollover threat detection and rollover prevention. In this paper, the contour line of load transfer ratio (CL-LTR) and the CL-LTR-based vehicle rollover index (CLRI) are proposed, describing LTR threshold and LTR change rate precisely, providing an accurate prediction of vehicle rollover threat. In detail, the CL-LTR is proposed via the roll dynamics phase plane analysis, and its analytical solution of one-degree-of-freedom vehicle roll model and extension for full vehicle are derived. Moreover, the predictive CLRI is proposed and evaluated via vehicle dynamics study. The results demonstrate that vehicle rollover threat is predicted accurately based on the CLRI, which shows benefits for the vehicle rollover prediction and stability control.     

一种适用于船舶轴舵系一体化安装的新型装备

研制一种船舶轴舵系一体化安装的新型装备。该装备采用2级导轨布置的结构对轴舵系进行安装,克服船舶尾部狭小空间的限制,现场安装与拆卸便捷,可缩短前期安装准备及拆卸时间。该装备集成电控系统及液压顶升系统,在安装过程中自动化程度提高较大,省去烧焊吊码工序,可大幅提高安装效率与精度,降低人工操作强度,消除安全隐患,提高船舶建造的智能化水平。该装备在船舶行业具有较高的实用推广价值。