大粒径ATB高温稳定性研究

借鉴国内外沥青混合料设计方法进行大粒径沥青稳定碎石基层配合比设计,根据路基实际情况,通过车辙试验,分析不同温度下不同级配大粒径沥青稳定碎石的高温稳定性,试验结果表明：大粒径沥青稳定碎石具有较好的高温稳定性。     

沥青稳定碎石基层力学特性及路用性能研究

通过对路用材料力学性能的两个重要指标,即劈裂强度和抗压回弹模量进行试验研究,以期对沥青碎石基层混合料的力学性能增加了解．同时与半刚性基层材料的相应数据进行对比分析．可为此类基层的推广应用提供参考。     

Structural Behavior of Continuous Prestressed Steel Fiber Reinforced High Strength Concrete Beam

The flexural behaviors of continuous fully and partially prestressed steel fiber reinforced high strength concrete beams are studied by experiment and nonlinear finite element analysis. Three levels of partial prestress ratio (PPR) are considered, and three pairs of two-span continuous beams with box sections varying in size are designed. The major parameters involved in the study include the PPR and the fiber location. It is concluded that the prestressed high strength concrete beam exhibits satisfactory ductility; the influences of steel fiber on the crack behaviors for partially prestressed beams are not as obvious as those for fully prestressed ones; steel fibers can improve the structural stiffness after cracking for fully prestressed high strength concrete beams; the moment redistribution from mid-span to intermediate support in the first stage should be mainly considered in practical design.     

舰船电力推进电机性能剖析

介绍了综合电力推进的概念、研究发展动态以及舰船电力推进电机的特殊性能要求,剖析了先进感应电机、轴向磁通永磁电机、横向磁通永磁电机、高温超导电机等高性能推进电机的性能特点、拓扑结构及关键技术.在分析推进电机研究应用现状的基础上对其未来发展进行了展望.     

Strength Regularity and Failure Criterion of High-Strength High-Performance Concrete under Multiaxial Compression

Multiaxial compression tests were performed on 100 mm × 100 mm × 100 nun high-strength high-performance concrete (HSHPC) cubes and normal strength concrete (NSC) cubes. The failure modes of specimens were presented, the static compressive strengths in principal directions were measured, the influence of the stress ratios was analyzed. The experimental results show that the ultimate strengths for HSHPC and NSC under multiaxial compression are greater than the uniaxial compressive strengths at all stress ratios, and the multiaxial strength is dependent on the brittleness and stiffness of concrete, the stress state and the stress ratios. In addition, the Kupfer-Gerstle and Ottosen's failure criteria for plain HSHPC and NSC under multiaxial compressive loading were modified.     

混凝土的温度时效研究

混凝土结构在遭受火灾作用后,在决定修复受损结构之前,必须估算结构的残余承载能力,这需要了解结构在高温作用后的性能,对相同配合比的混凝土试件在温度作用后的力学性能进行了初步的试验研究,包括抗压强度和横纵向应变,并分析了其变化规律,为高温后混凝土的温度时效研究提供了参考。     

掺加聚丙烯纤维改善混凝土性能的研究

针对混凝土的抗变形能力差、耐磨性差等缺点,在混凝土中掺加一定量的聚丙烯纤维,通过聚丙烯在水泥混凝土中的阻裂、增韧机理。来增加混凝土的强度、韧性及耐腐蚀性等,可以延长混凝土路面的使用寿命。     

基于神经网络的高温下（后）预应力损失分析

提出了基于神经网络的高温下(后)预应力损失的评价方法.针对影响高温下(后)预应力损失的复杂多变性和相当强的不确定性,建立了基于神经网络的高温下(后)预应力损失模型.运用神经网络强大的自适应、自组织、自学习的能力以及高度的非线性映射性、泛化性和容错性的特点,通过对训练样本的神经网络学习,建立了预应力损失与温度、初始有效预应力以及高温条件的网络关系,最终实现了对测试样本的预应力损失预报.     

曲轴系多学科行为耦合研究现状、讨论与展望

论述了曲轴系多学科行为耦合分析的研究现状和最新进展,讨论了曲轴系多学科行为耦合分析目前存在的问题和不足,分析了曲轴系多学科行为耦合分析的特点和解耦方法。指出开展多工况、计入多种影响因素的曲轴系多学科行为耦合分析、试验研究和专门的应用软件开发是曲轴系多学科耦合研究有待于进一步深入研究的课题。     

高功率密度柴油机智能冷却系统设计研究

对高功率密度柴油机智能冷却系统进行了简介,概述了国内外发展现状,总结了我国在高功率密度柴油机智能冷却系统研究方面与国外的差距,提出了我国高功率密度柴油机智能冷却系统设计的总体方案、CFD仿真方法、控制策略及智能控制系统软硬件的构成,并对今后的工作进行了展望。