不同状腿结构的自升式平台对比分析(英文)

The jack-up unit is one of the best drilling platforms in offshore oil fields with water depth shallower than 150 meters.As the most pivotal component of the jack-up unit,the leg system can directly affect the global performance of a jack-up unit.Investigation shows that there are three kinds of leg structure forms in the world now:the reverse K,X,and mixing types.In order to clarify the advantage and defects of each one,as well as their effect on the global performance of the jack-up unit,this paper commenced to study performance targets of a deepwater jack-up unit with different leg systems(X type,reverse K type,and mixing type).In this paper a typical leg scantling dimension and identical external loads were selected,detailed finite element snalysis(FEA) models were built to simulate the jack-up unit’s structural behavior,and the multi-point constraint(MPC) element together with the spring element was used to deal with the boundary condition.Finally,the above problems were solved by comparative analysis of their main performance targets(including ultimate static strength,dynamic response,and weight).     

固态断路器中快恢复二极管的反向恢复模型

本文简要阐述了固态断路器中快恢复二极管的反向恢复问题,详细分析了二极管的关断过程,建立了二极管反向恢复的集总电荷模型,并在Matlab\Simulink中进行了实现。仿真结果和产品数据手册保持一致,验证了模型的有效性和实用性。     

虚拟海浪海洋环境模拟方法及应用

根据海浪理论及随机海浪的模拟方法和方钟圣所著《西北太平洋波浪统计集》的波浪资料,设计并编制了虚拟海浪海洋环境模拟软件,将《西北太平洋波浪统计集》的80个区块3 600份数据表的所有数据全部录入海洋环境数据库,初步完成了虚拟海浪海洋环境模拟流程和数据库界面的设计,将海浪虚拟化.以结构强度虚拟测试为例,介绍了外载定义过程船舶航行海况的设置方法,得到了海浪谱曲线和海况的波面运动图.研究结果表明:动态海况的显示技术和海洋环境数据库的配合使用,为船舶结构强度和总体性能虚拟测试提供了良好的测试环境.     

吉利4D20轿车柴油机轻量化技术应用研究

节能减排是发动机设计的核心目标,采用轻量化技术是实现节能减排的有效措施之一.分别对吉利4D20轿车柴油机气缸体、气缸盖、梯型框架和油底壳、双质量飞轮、活塞及连杆、气缸盖罩和链条罩盖等关键零部件的轻量化技术进行了应用分析.吉利4D20轿车柴油机大量采用铝合金以及经过优化设计轻量化结构,使其单位功率质量达到2.12 kg/kW.     

一种电动车电路故障防护新方法

作为保证电动汽车正常运行的水泵支路,在实际运行中有可能出现多种故障.论文从实际出发,对电机回路异常导致的功率电阻爆炸故障进行分析,并给出检测防止故障的方法.对电动汽车水泵支路功率电阻上的电压进行实时监测,并与标准曲线做相关度分析.以相关度作为判断水泵支路电机部分是否发生异常的判据,在支路故障时及时断开支路以保证支路安全.     

自锚式悬索桥主缆成桥线形计算方法

该文针对自锚式悬索桥主缆成桥线形的求解,介绍了抛物线法和分段悬链线法的原理和实际应用方法,并结合工程实例对两种方法进行了对比计算分析,同时,对影响抛物线法精度的主要参数进行了探讨。     

龙华港双层钢桁架连续梁主桥建造技术

该文介绍了龙华港双层钢桁架连续梁主桥的工程概况和结构特点,分析了主桥建造过程中的建造难点,阐述了建造的总体思路,针对建造过程的几项关键技术进行了较详细的说明。     

双中间轴变速器CA10TA190M的设计开发

分析了双中间轴变速器功率分流、齿轮浮动、轴浮动等的特点,阐述了该类型变速器中心距、齿轮承载力的设计理论及优势 在理论研究的基础上,通过变速器中心距确定、载荷谱设计、齿轮设计、轴的布置及设计、轴承及润滑设计、副箱承载能力设计、副箱同步器及主箱换挡滑动齿套设计等,完成了双中间轴变速器CA10TA190M的设计开发.     

Reliability Analysis of Systems with Common Cause Failure Based on Stress-Strength Interference Model

Many mechanical systems have the characteristics of multiple failure modes and complex failure mechanisms. On the basis of stress-strength interference (SSI) model, this paper takes the mechanical system with common cause failure (CCF) as the research object. The relationship between the stress distribution and the strength distribution is studied, and the failures of components are independent of each other under the deterministic stress. Then, the concept of conditional reliability is introduced to build the system reliability models under the action of one-stress and multi-stress for both series and parallel systems. Finally, the corresponding properties of the proposed methods are discussed to show their advantages.     

Reliability Analysis of Aero-Engine Main Fuel System Based on GO Methodology

To improve the reliability of an aero-engine main fuel system, the quantitative and qualitative reliability analysis of the system is conducted based on goal oriented (GO) methodology. The quantitative reliability analysis results and the minimum cut sets of the fuel system are obtained, respectively. These results are compared with the results of the FTA (Fault Tree Analysis) method, and the comparison result shows GO method is rational and applicable. Therefore, it is feasible to apply the GO method in the reliability analysis of an aero-engine main fuel system.