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1.
针对6自由度动力总成悬置系统分析振动响应不足的问题,文章在Matlab中建立了基于整车基础的动力总成悬置系统13自由度模型,并通过模态试验进行了验证;考虑到能量解耦法的固有缺点,提出以提高能量解耦率和悬置隔振率为稳健性目标函数,基于多目标粒子群算法对悬置系统进行隔振优化。仿真和试验结果表明,基于该方法的悬置系统隔振优化在提高悬置系统能量解耦率的同时,发动机悬置的隔振率也得到不同程度的提高。  相似文献   

2.
发动机悬置系统对降低整车振动和噪声有显著影响,为得到满意的悬置系统特性,在设计时往往需要对悬置参数进行多次修改;文章通过求解悬置系统固有频率以及能量解耦方法进行悬置参数计算,并应用Matlab对轻卡悬置系统模态及能量解耦进行计算,在此基础上应用Adamas软件进行优化,在实际应用中取得了良好的效果。  相似文献   

3.
根据悬置系统设计的基本理论,对悬置系统进行了动力模态分析;在模态分析基础上,建立悬置系统优化设计的数学模型,对悬置系统的能量解耦度和谐振频率进行了优化设计。  相似文献   

4.
针对轮式装载机在怠速NVH性能差的问题,提出了一种基于Kriging模型的动力总成悬置系统的优化设计方法.建立了包含动力总成系统的整车虚拟样机模型.结合最优拉丁超立方试验设计、Kriging近似模型以及NSGA-II多目标优化方法,选取悬置的刚度作为设计变量,以动力总成系统解耦度、驾驶室地板垂向加速度以及底盘动能作为目标函数进行优化,得到Pareto前端.通过权重系数法求得最优解,并通过整车模型进行验证.结果表明,该方法能够快速有效地对悬置系统进行优化,优化后的悬置系统解耦率得到提升,同时,优化后的整车模型在模拟的5个稳态工况下,驾驶室的振动及底盘动能均有所降低,驾驶室振动最大降幅为23.6%,(怠速),底盘动能最大降幅为22.0%(2,000,r/min),整车平顺性得到提升.  相似文献   

5.
为了提高电驱动动力总成在行驶过程中的性能,对某款小型纯电动轿车配置的电驱动2AMT动力总成悬置系统进行了优化设计。基于ADAMS多体系统软件,建立了电驱动2AMT总成悬置系统的六自由度振动模型,并进行了系统模态分析和载荷工况下的变形仿真,根据分析结果,以提高解耦率为优化目标,选取悬置三向刚度作为设计变量,利用粒子群遗传(PSO-GA)混合算法,对悬置系统进行了优化设计。仿真结果表明,优化后悬置系统的解耦率可以满足设计要求。  相似文献   

6.
为了提高电驱动动力总成在行驶过程中的性能,对某款小型纯电动轿车配置的电驱动2AMT动力总成悬置系统进行了优化设计。基于ADAMS多体系统软件,建立了电驱动2AMT总成悬置系统的六自由度振动模型,并进行了系统模态分析和载荷工况下的变形仿真,根据分析结果,以提高解耦率为优化目标,选取悬置三向刚度作为设计变量,利用粒子群遗传(PSO-GA)混合算法,对悬置系统进行了优化设计。仿真结果表明,优化后悬置系统的解耦率可以满足设计要求。  相似文献   

7.
发动机悬置系统多目标优化设计   总被引:8,自引:0,他引:8  
在研究发动机悬置系统各种优化设计方法的基础上,以整车人机系统为背景,提出以人体在垂直方向振动加速度均方根加权值最小和发动机悬置系统能量解耦为目标的多目标优化模型,对发动机悬置参数进行了优化。计算实例表明,选择合适的发动机悬置参数可以有效地降低汽车振动,改善汽车乘坐适合性。  相似文献   

8.
为提高动力总成液压悬置系统的隔振性能,文章考虑了惯性通道解耦盘式液压悬置的幅频非线性特性,通过对液压悬置的上液室刚度和惯性通道内液阻进行参数识别,建立了具有幅频特性的液压悬置动刚度模型,并通过试验数据验证了该模型的准确性;在整车二自由度模型的基础上,采用模式搜索算法对液压悬置的内部参数、车身的传递系数和车身的传递加速度系数进行了优化设计。结果表明,该优化设计方法优化效果良好,而且在怠速工况下悬置传递到车身的动反力明显降低。  相似文献   

9.
针对XMQ6838Y客车怠速时方向盘抖动和座椅振动剧烈的问题,以其动力总成悬置系统各阶模态的解耦率最大为目标和固有频率的分配为约束,构建一种以悬置元件离散刚度与连续位置为设计变量的优化设计模型.通过建立系统自由振动模型,获取其固有频率和六阶模态;利用能量解耦法,求解系统六自由度的解耦率.在MATLAB和iSIGHT集成条件下,采用刚度离散化的方法和自适应模拟退火算法,优化悬置系统设计参数.实验结果表明:优化后,该车型在启、闭空调时方向盘和各排座椅的三向振动均明显降低,尤其在开启空调时,方向盘Y向振动加速度由3.43 m·s-2下降至0.35 m·s-2,提升了乘坐舒适性.  相似文献   

10.
轿车发动机动力总成悬置系统优化研究   总被引:1,自引:1,他引:1  
该文应用复合三线摆测量法测得了某轿车动力总成的有关参数。建立了动力总成悬置系统动力学模型,应用ADAMS进行了动力学仿真分析;合理配置各阶固有频率;综合运用弹性中心理论和能量解耦方法对动力总成悬置系统进行了优化设计。根据优化结果进行了试验,证明动力总成悬置系统的隔振性能有了明显提高,主要测点的振动程度下降了10%~30%,有效地降低了轿车动力总成悬置振动。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

18.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

19.
20.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

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