BOSCH热膜式空气质量流量传感器的分析

本文主要对BOSCH公司的热膜式空气质量流量传感器做了详细的分析研究。首先对空气流量质量传感器在汽车上的重要性进行了简单地叙述,接着重点分析了BOSCH公司的热膜式空气质量流量传感器,最后对汽车空气质量流量传感器的前景进行了展望。     

汽车动力总成悬置系统优化与试验研究

以某款国产汽车为研究对象,在ADAMS中建立动力总成悬置系统的动力学模型。利用参数化分析方法,讨论了悬置参数对系统隔振性能的影响。对悬置参数进行优化,并分析比较优化前后的结果,优化后的悬置系统的隔振效果得到明显改善,并进行实车试验验证。     

等效波的散货船舱口角疲劳评估应力组合方法(英文)

The stress combination method for the fatigue assessment of the hatch corner of a bulk carrier was investigated based on equivalent waves.The principles of the equivalent waves of ship structures were given,including the determination of the dominant load parameter,heading,frequency,and amplitude of the equivalent regular waves.The dominant load parameters of the hatch corner of a bulk carrier were identified by the structural stress response analysis,and then a series of equivalent regular waves were defined based on these parameters.A combination method of the structural stress ranges under the different equivalent waves was developed for the fatigue analysis.The combination factors were obtained by least square regression analysis with the stress ranges derived from spectral fatigue analysis as the target value.The proposed method was applied to the hatch corner of another bulk carrier as an example.This shows that the results from the equivalent wave approach agree well with those from the spectral fatigue analysis.The workload is reduced substantially.This method can be referenced in the fatigue assessment of the hatch corner of a bulk carrier.     

液舱晃荡与浮体非线性耦合运动分析(英文)

Nonlinear interactions among incident wave, tank-sloshing and floating body coupling motion are investigated. The fully nonlinear sloshing and body-surface nonlinear free surface hydrodynamics is simulated using a Non-Uniform Rational B-Spline (NURBS) higher-order panel method in time domain based on the potential theory. A robust and stable improved iterative procedure (Yan and Ma, 2007) for floating bodies is used for calculating the time derivative of velocity potential and floating body motion. An energy dissipation condition based on linear theory adopted by Huang (2011) is developed to consider flow viscosity effects of sloshing flow in nonlinear model. A two-dimensional tank model test was performed to identify its validity. The present nonlinear coupling sway motion results are subsequently compared with the corresponding Rognebakke and Faltinsen (2003)’s experimental results, showing fair agreement. Thus, the numerical approach presented in this paper is expected to be very efficient and realistic in evaluating the coupling effects of nonlinear sloshing and body motion.     

基于经验模态分解的大型轮船锚机齿轮箱故障诊断

经验模态分解法(EMD)是一种针对信号变化的自适应处理方法。针对某大型轮船锚机齿轮箱,首先通过测量不同转速和位置的振动信号预估故障源;其次对采集出的原始故障信号进行处理,提取故障特征,即通过EMD将原始信号分解为若干个IMF分量,不同的IMF分量包含不同频段所对应的能量,然后再对IMF分量进行包络分析和谱分析,最终便可确定故障源,并对其进行修复。通过测试比较,验证了EMD理论方法的正确性和有效性。     

车辆排气系统模态和振动特性及组件敏感性研究

建立排气系统有限元模型并进行了验证.利用所采集的加速度信号作为边界条件,计算分析了排气系统吊钩的动态响应力.结果表明,在发动机激励作用时,吊钩载荷响应力和加速度在同一频率出现峰值,且处于弯管处的吊钩由于有附加扭矩而造成动态响应力较大.对吊耳刚度进行敏感性分析,发现排气系统对吊耳Z向刚度较敏感.因此可以通过优化吊耳Z向刚度来减小吊钩处动态响应力.     

湖南省高速公路沥青路面裂缝病害调查与原因分析

介绍了湖南省高速公路沥青路面裂缝病害的调查情况及相关结论,并对湖南省高速公路沥青裂缝病害产生的原因进行了分析,在此基础上对湖南省高速公路沥青路面的设计、施工及养护均提出了相关建议。     

服役混凝土梁桥承载能力时变模型分析与应用

阐述分析了锈蚀钢筋与混凝土粘结性能、混凝土碳化衰减性能、混凝土抗压强度的时变性能、锈蚀钢筋力学性能及不同受力状况等对混凝土梁桥性能退化的影响。通过工程实际和研究,在已有资料的基础上,改进了服役钢筋混凝土梁桥承载能力模型。研究的理论基本上解决了服役混凝土梁桥的承载力评定和预测问题,为旧桥的可靠性评估奠定了基础。最后,通过工程实例的计算,具体说明了梁桥承载力验算的方法以及理论与实际的符合情况。     

基于驾驶人换道行为的换道决策辅助系统预警时间研究

基于驾驶人的换道操作行为初步提出换道决策辅助系统合适的预警时间。观察换道作业与目标车道跟随车辆之间的联系。实验在西安绕城高速公路某一路段上实现。     

自动加油系统在某型高机动电源车的应用设计

从提升电源车自动化保障程度角度出发,阐述了在电源车内加装自动供油系统的必要性,针对电源车内部布局特点,分析了储油箱位置选取和结构工艺要求,提出了最佳方案,并给出了自动加油控制电路的原理框图,介绍了自动加油系统油位保护功能,目前该项设计已实际应用。