后装压缩式垃圾车液压系统及控制系统设计

压缩式垃圾车近年来发展迅速,但制造水平参差不齐,通过对某后装压缩式垃圾车液压系统及控制系统的设计分析,介绍了一种高效率、高可靠性、高智能化的大型压缩式垃圾车,为压缩式垃圾车的发展提供了一种有效的途径。     

大直径PHC桩竖向承载特性数值模拟研究

以珠海高栏港码头结构为工程背景,对码头的大直径PHC桩的数值模拟技术和承载特性进行研究。首先采用ABAQUS进行数值模拟,并将数值模拟结果与试验结果进行对比分析,验证了有限元分析的可行性,然后通过桩径、桩长,桩侧土和桩端土等一系列参数的变化,探讨这些参数对PHC桩Q-S曲线的影响。结果表明,有限元计算出的位移比实测结果高出2%~20%,桩长超过50 m的PHC桩属于超长桩。     

车载信息系统操作对驾驶员动作分神的影响

车载信息系统的使用,在为驾驶员提供较为舒适车内驾驶环境的同时,还给驾驶员带来了不可忽视的分神问题.以多资源理论为基础,对驾驶员动作分神进行界定,选择车载收音机、CD、MP3 和导航仪作为车载信息系统研究对象,基于实验测试,定量分析车载信息系统操作对引起的驾驶员动作分神规律,并对导致驾驶动作分神的因素进行显著性分析.结果表明,交通环境和车载信息系统操作对驾驶人动作分神具有显著影响,车载收音机操作对动作分神影响不大,MP3 调节时手离开方向盘时间增加超过8.56%,冲突或差错率增加9.72%,导航仪路径输入时手离开方向盘时间显著增加,冲突或差错率增加 28.17%,语音路径诱导时刹车操作差错增加.     

交通振动对邻近古建筑的动力影响测试分析

对北京地铁2号线和在建直径线邻近古建筑（明城墙遗址和京奉铁路正阳门老车站旧址）现场测试,评估其在既有地铁交通和路面交通作用下的振动响应,并研究古建筑结构振动响应的传播规律.测试结果表明：1）时域内,古建筑结构在地铁运营下的振动响应是路面交通的10倍左右;交通振动引起古建筑结构的动力响应随水平距离和竖直距离呈规律改变,且古建筑结构以水平方向动力响应为主;2）频域内,地铁交通引起古建筑响应的主要频段是40-90 Hz,路面交通引起古建筑响应的主要频段是10-20 Hz,且路面交通引起的古建筑振动速度在一定范围内出现放大现象.     

石墨尾矿在底基层中的应用

通过试验验证了水泥稳定石墨尾矿砂做底基层的可行性,并在试验段中验证了其适用性,通过在施工中的不断完善和应用,得出了最佳组成配比,且效益良好。     

异地分布式桥梁结构远程协同拟动力试验

为了解决现代工程结构日趋复杂化与单个实验室的规模及试验能力之间的矛盾,介绍了桥梁结构远程协同拟动力试验的基本原理、数值积分方法及应用程序的开发。针对目前结构试验中广泛使用的MTS系统,提出了2种不同的控制方法来实现试验程序与MTS控制系统的连接。利用网络化结构实验室系统NetSLab在美国南加州大学及中国3所高校之间进行了六跨桥梁结构的远程协同拟动力试验。试验结果表明：该系统可将异地分布的单一结构实验室通过互联网连接在一起,形成功能强大的网络结构实验室以进行大型桥梁结构系统的远程协同拟动力试验,从而提高综合试验能力,并达到资源共享的目的。     

大曲率船体球面零件压制减薄规律

试验结果表明大曲率船体球面零件在压制成型后同时存在增厚和减薄情况，最大减薄出现在零件中心外围区域，零件边缘区域增厚现象较明显。进一步分析零件成型前后的板厚数据变化情况，总结大曲率船体球面零件压制成型的减薄规律及实际加工的注意事项，并建立压制减薄风险控制流程，可有效避免大曲率船体球面零件压制减薄现象成为结构建造的潜在风险。     

Trapped waves within the blocking frequency under compressed sea ice and two-dimensional current

The existence of trapped modes due to a horizontal submerged rigid cylinder placed below a compressed ice-covered surface is shown to exist within the frequency band of wave blocking by employing linearized water wave theory and with the inclusion of the effects of a two-dimensional current and the obliqueness of the propagating wave. A new modified multipole expansion method catering to the multiple propagating modes is proposed. The impact of different choices of propagating modes at a fixed frequency within the above-mentioned band on the trapped modes is detailed. Multiple trapped modes whose number depends on the direction and magnitude of the current exist within the frequency band. Out of the three choices of current types considered, while two of them result in the generation of trapped modes for all three possible choices of the propagating wave, the remaining one shows that only one propagating mode can generate a trapped wave. A break in the continuous spectrum of the trapped mode frequency due to the wave blocking and at the point of inflexion is presented. There exists a region of angle of propagation within which an abundance of the trapped mode is shown. The surface profiles for different angles of propagation and choices of propagating modes are illustrated graphically. The trapped modes associated with a higher angle of propagation decay at a faster rate.     

Centrifuge performance of LCSM wall reinforced pile-supported wharf subjected to yard load-induced marine slope soil movement

Lattice cement soil mixing (LCSM) walls are constructed to relief the marine slope soil movement that will trigger failure of the pile-supported wharf, the structural performance and pile-soil interactions after the LCSM implementation are major concerns. This paper investigated motion modes, load-displacement relations, soil and pore pressures, and bending moments of pile-supported wharfs with LCSM walls subjected to yard load-induced slope soil movement via centrifuge modeling. Results showed that the LCSM wall tilted to compress the soil and pile, inducing the tilting of the wharf. The lateral structural displacement was effectively restricted by the LCSM wall compared with that of a nonreinforced wharf, but the LCSM wall was not superior to the other lattice wall type with legs in limiting the lateral structural displacement, and the deep LCSM wall worked better at larger soil movement. The rear piles were evidently affected by slope soil movement and were compressed in the middle part. Soil pressures generally increased with increasing yard loads, whereas their distributions were deeply affected by different LCSM wall depths. Pore pressures were greater around the tilting LCSM wall because of larger soil shear areas but dissipated when soil movement stopped. Bending moment distributions indicated evident waterside curvatures in rear piles, whereas waterside curvatures occurred in the upper part and landside curvatures occurred in the lower part in front and middle piles, the effects of LCSM wall types and depth on bending moment distributions were tremendous.     

考虑损伤下的汽车吸能盒轴向压缩特性研究

用有限元软件ABAQUS对钢质、铝合金质吸能盒的吸能特性进行对比研究，采用不同的损伤模型模拟材料的变形行为，比较了两种吸能盒轴向压缩距离、变形模式、评价指标的变化特性。结果表明，数值模拟下吸能盒的轴向压缩距离和变形模式与试验结果吻合。在冲击速度为10 m/s的低速碰撞下，铝合金质吸能盒吸收的能量与钢质吸能盒相比减少了6%；钢质吸能盒的吸能效率为35.5 kJ/mm，比铝合金质吸能盒高。铝合金质吸能盒相较于钢质吸能盒在压缩过程中形成了明显的折叠褶皱，边缘处材料失效，单元被移除。吸能盒的评价指标中铝合金质吸能盒的比吸能 （SEA）、峰值碰撞力 （PCF） 均比钢质吸能盒更优，钢质吸能盒的吸能量 （EA）、平均碰撞力 （MCF） 比铝合金质吸能盒更优。铝合金相比钢更适合作为中低速碰撞时车用吸能盒的材料。