研究试验
- 与 研究试验 相关的网络例句 [注:此内容来源于网络,仅供参考]
-
The basic approach of protecting people from being hurt or killed in an accident is to improve crashworthiness of vehicles. This paper starts with discussing theories and methods for vehicle passive safety design, which included experiential methods, analytic methods, multi-body dynamics methods, crash test methods and the finite element method. Emphasis will be paid to the basic FEM theories and algorithms of impact problems. Topics discussed include the governing equation, element discretization, hourglass control, time integration, material model, shell element algorithms and contact-impact algorithms. For more reliable simulation results, this paper then conducts study on how to accurately get material model parameters by combining the FEM method with experimental method, and develops relevant material test machine and parameter calculating software. Based on that, basic typical impact simulation and test validation study are conducted. On the basis of the above work, the paper studies the thin-shell structures'crashworthiness, which was affected by the following factors: spot-weld features, shell thickness, cross-section and pre-deformation. As to vehicle parts'crashworthiness, the paper conducts simulation study of designing energy-absorbing steering system and adaptive airbag system. A practical energy-absorbing steering wheel is designed as an example. In further depth research, the paper suggests several inverse quantificational methods for vehicle crashworthiness design based on the ideal crash characteristics. The above theories and methods are applied with good results through several practical vehicles' crashworthiness design and improvement.
文中对汽车碰撞安全性的设计理论和方法进行了归类和总结,其中包括经验法、解析法、多刚体动力学法、试验法以及有限元方法等;重点介绍了碰撞有限元法的基本理论和有关算法,涉及到有限元求解控制方程、单元离散、沙漏模态控制、时间积分、材料模型和应力修正、薄壳单元算法以及接触碰撞界面算法等,探讨了有限元计算中的材料模型参数获取技术,开发了相应的材料试验装置及材料模型参数反求软件,在此基础上进行了基本的碰撞仿真算例和试验对比研究;文中通过应用有限元方法研究了薄壁构件的碰撞吸能特性,指出了设计薄壁吸能构件时需要考虑的几个主要影响因素,即焊点、壁厚、横截面和预变形等;在关于车辆部件的碰撞安全性能设计中进行了吸能转向机构和自适应安全气囊的仿真研究,提出了吸能转向机构和自适应安全气囊的仿真研究方法;文中最后探讨了整车碰撞性能的设计与改进方法,提出了以理想碰撞特性为目标,采用分段加速度或者根据碰撞时间进行设计的反推设计法、部件吸能仿真优化设计法等量化设计方法,并通过综合应用文中所讨论的相关技术进行了整车碰撞性能的设计与改进实例研究,所选定的车型是大众化的普通轿车和碰撞安全性基础较差的微型面包车,研究结果表明,本文所提出的设计与改进方法是适用而有效的,具有重要的工程实用意义和价值。
-
To accelerate the widespread of Synchronous Chip Seal and improve the operation quality of Synchronous Chipsealer, key techniques which influence the operation quality is studied detailedly, including the control of distributing quality, the dynamics characteristics of hydraulic system and the spray characteristics of asphalt nozzle of Synchronous Chipsealer.1 The factors which influence Synchronous Chip Seal quality are studied. Fiducial probability of simultaneous distribution density is advised to be used in evaluating the distribution bias and standard deviation of asphalt and aggregates simultaneously, which is more advanced than the single index evaluation method used before.2 The volume efficiency formula of asphalt pump is revised after analyzing the data of volume efficiency with mathematical statistics, which is helpful to match the asphalt spray system and control the flow out of asphalt pump accurately. With equation deduction and experiment, dynamic of hydraulic system used in Synchronous Chipsealer is studied, which lay the theory foundation on improving the stability and efficiency from design and controlling.4 Simulation on hydraulic system used in Synchronous Chipsealer is done with AMESim; the results indicate that multi-circle parallel connected hydraulic system with constant pressure power is better than that with load-sensing pressure power at present, because the latter will oscillate when the multi circles work at the same time. This conclusion has been proved during the debug of Synchronous Chipsealer.5 Asphalt nozzle characteristics, such as flat jet shape, flow distribution, are studied with experiment, the results indicate that cross quality of asphalt distributing is not increased linearly follow the increase of fan overlap level, the best point usually exists between two whole overlap level, asphalt distributing quality is better than±4% at the 2.5 overlap level, meets the superior specified in standard; The distribution quality of Synchronous Chipsealer can be increased by spray asphalt of different flow rang with nozzle of different diameter
为了加快同步碎石封层技术的推广,提高同步碎石封层设备的作业质量,本文对同步碎石封层设备作业质量的影响因素与控制方法、液压系统的动力学特性和沥青喷嘴的喷洒特性等关键技术进行了深入细致的研究:1研究了影响同步碎石封层作业质量的因素,提出了采用联合密度分布置信概率对同步碎石封层中沥青洒布量和碎石撒布量的系统偏差和标准差指标进行综合评价的方法,克服了传统评价方法只能对单一指标进行评价的缺陷;2采用数理统计的方法,研究了沥青泵的容积效率特性,修正了沥青泵容积效率公式,为沥青喷洒系统的匹配和沥青泵出口流量的精确控制提供了依据;采用数理方程推导与试验相结合的方法,研究了同步碎石封层设备液压系统的动力学特性,为从设计和控制的角度提高同步碎石封层设备液压系统的稳定性和效率奠定了理论基础;3运用AMESim软件对采用负载敏感控制和恒压控制的两种同步碎石封层设备液压系统进行仿真,结果表明:负载敏感控制的并联液压系统在多回路同时工作时,由于液压泵排量控制参考压力不稳定,容易引发液压系统振荡,恒压控制的并联液压系统是目前技术条件下比较理想的同步碎石封层设备工作装置驱动方案;该结论亦通过同步碎石封层设备装机试验得到了验证。4采用试验的方法对沥青喷嘴的喷洒特性进行了研究,结果表明:沥青洒布的横向精度并不是随着喷洒扇面重叠度的增加线性增加,其最高点通常出现在二个重叠度之间的"半重叠位置","2.5重叠"洒布时,沥青的横向洒布精度≤±4%,可以达到国家相关标准中的优级标准;同步碎石封层设备还可以根据不同洒布量情况下的流量需求,采用不同通径的喷嘴进行喷洒,提高沥青洒布精度。
-
Primary results are shown as followings: 1. PH measuring results of soil solution and eluviation solution show that the ability of experimental plot the acid buffer capacity of soil is stronger under the experiment condition,there is no obvious acidification in soil which after acid rain eluviation. The result has substantial differences with that gotten by most of investigationers in similar work before.
这一结果与以往类似研究中多数研究者得到的结论存在本质区别,原因可能在于此次试验的试验条件与以往研究的试验条件不同,其中最主要一点是在本次试验中使用的土壤样品的重量比以往试验均显著增大,而且使用的是土壤结构和组成等均未经破坏的原位土,从而使入渗酸雨与承受酸雨沉降的土壤之间的比例关系更接近自然酸雨沉降过程,以此为基础得到的试验结果应该更加客观、可靠。
-
In order to complete the investigation, impersonality feasible experiment solutions and devices are designed independently to systemically investigate on activation and transfer characteristic of soil heavy metal under acid rain effect. Primary results are shown as followings:1. PH measuring results of soil solution and eluviation solution show that the ability of experimental plot the acid buffer capacity of soil is stronger under the experiment condition,there is no obvious acidification in soil which after acid rain eluviation.The result has substantial differences with that gotten by most of investigationers in similar work before.
这一结果与以往类似研究中多数研究者得到的结论存在本质区别,原因可能在于此次试验的试验条件与以往研究的试验条件不同,其中最主要一点是在本次试验中使用的土壤样品的重量比以往试验均显著增大,而且使用的是土壤结构和组成等均未经破坏的原位土,从而使入渗酸雨与承受酸雨沉降的土壤之间的比例关系更接近自然酸雨沉降过程,以此为基础得到的试验结果应该更加客观、可靠。2、酸雨对盐基离子活化迁移产生的影响勿庸置疑,但是,在盐基离子活化迁移的过程中,并没有出现预想中的重金属元素活化迁移现象,表明土壤中的重金属元素并不如理论分析的那样对酸雨沉降反应敏感。
-
Based on investigating the short and intermittent structural plane, surrounding rockmass of the huge underground powerhouse in Three Gorge has been divided into five statistical similar areas according to its characteristic of rockmass structure by applying structure plane network simulation. Distributed characteristic of structural plane has been studied and based on it mechanics macrocharacteristic has been studied:(1) It is the first time that based on the result of structural plane network simulation rockmass quality of every structure area has been studied with applying blurred information optimum seeking technique and be compared with and RQD method. The result indicated that it has better effect to evaluate rock quality with blurred information optimum seeking technique.(2) It is the first time that the interrelated relationship of the result of in-suit rockmass deformation test and fractal characteristic of structure on test point has been applied to determine rockmass deformation parameter. The question of evaluating deformation parameters of engineering rockmass has been solved.(3) Anisotropy strength parameters have been determined by applying shear zones simulating method. The result indicated that there are different strength parameters in every structural area, after comparing the result of Fast Lagranian Analysis in continua number simulation method with that of method of weighted mean according to continuity. The result indicated that when a suitable reduction coefficient is been considered rockmass strength parameters can be simply and fast determined with method of weighted mean according to continuity where there is not enough test result.(4) Damage characteristic has been studied based on analysis fractal characteristic of structural plane network by applying fractal-damage coupling method. It is the first time that the concept of damage degree has been set up to evaluate rockmass quality according to the biggest principal damage.
通过对短小、断续性结构面统计特征的研究,将地下厂房区划分为五个岩体结构统计均质区,应用结构面网络模拟技术研究了各个岩体结构均质区结构面的发育分布特征,并以此为基础对岩体宏观力学特性进行了深入研究:(1)首次通过在结构面网络模拟计算结果的基础上,应用模糊信息优化技术研究了厂房区各个岩体结构分区的岩体质量并与岩体基本质量指标研究法、岩体质量指标RQD值研究法作了对比,结果表明以结构面网络模拟结果为基础,应用模糊信息优化技术进行岩体质量评价能够取得很好的效果,解决了工程岩体质量的定量评价问题;(2)首次通过对已有的现场大型岩体变形试验结果的分析及相应试验点岩体结构分形特征的研究,建立了结构面分布的分形维数和岩体变形指标间的相关关系,并首次应用这种相关关系根据结构面网络模拟及分形维数计算结果确定了缺少试验结果的地下厂房各工程部位的岩体变形指标而且应用于围岩稳定性计算,解决了工程岩体宏观变形参数的评价问题;(3)应用在结构面模拟网络图上模拟岩体剪切破坏带的方法,得出了岩体在不同方向上的强度参数,结果表明岩体的强度特性与结构面的发育方向和程度有着明显的关系,各个岩体结构均质区具有不同的强度参数;同时还通过应用拉格朗日差分法对岩体强度指标的数值分析并与按连通率加权平均计算法对比表明,按连通率加权平均计算法在考虑合理的折减系数情况下,可以简单快速地对缺少现场大型试验结果的具体工程部位实现岩体强度指标的估计,通过以上研究解决了工程岩体抗剪强度参数的评价问题;(4)通过结构面网络分形维数的研究,应用分形损伤耦合分析方法,研究了厂房区岩体的损伤特征,并首次引入"损伤度"的概念,建立了应用最大主损伤评价岩体质量的指标体系。
-
Rice moisture content can be controlled by use of different consistency salt and acidliquor,the method of preparing different moisture contents rice sample also be studied and adopted.Such as, temperature humidity preservation box used in testing mechanical physical properties ofrice kernel, tensile and bending experiment device which can be used on rice samples. Configureddark box, CCD photography, image-taking system, pre-experiment to forcast mechanical physicalproperty and moisture transfer property, from which we can know that distance of elastic modulusand passion ratio in tensile process test is not big when renitency strength is much larger thanresist-pull strength, tensile test can be replaced by bending test to research tensile property ofrice, because tensile test is hard to do, experiment research methods and feasibility werediscussed, and suitable humid stress field experiment research plan ere made.
研究、采用了合适的盐溶液及不同浓度的酸溶液调节稻米含水率、制取不同含水率稻米试样的方法;研制了测量稻米材料机械物理特性时使用的保温保湿箱、适用于稻米试件使用的拉伸和弯曲试验装置;配置了暗箱、CCD摄像机、竖直与水平摄像装置及计算机图像采集系统等;进行稻米机械物理特性和水分传递特性的各种预备试验,得到:稻米的抗拉强度远小于抗压强度而拉压时的弹性模量、泊松比相差不大,稻米籽粒的拉伸试验难度极大,成功率很低,可以用籽粒的弯曲试验代替拉伸试验研究籽粒材料的拉伸特性;探讨试验研究方法及其可行性,制定了合理的稻米湿应力场试验研究方案。
-
The mechanical behavior of Shape Memory Alloys material is tested, and the constitutive model of the SMA is established. A kind of SMA combined rubber isolator is developed, and the isolation effect of the SMA combined rubber isolator for long-span bridge and tall building structures is numerically simulated, from which the adaptive isolation performance and the self-restoring capacity of the SMA combined rubber isolator are verified. A kind of SMA damper is developed, the mechanical behavior of the SMA damper is tested, and the model of restoring force of the SMA damper is established. The theory and method of adaptive control based on the SMA damper for the long-span bridge are built, and the effectiveness and reliability of the adaptive control for the long-span bridge using the SMA damper are verified through numerical simulation and model test. The MRF-04K type magnetorheological damper is developed, the mechanical behavior of the MR damper is tested, and the model of restoring force of the MR damper is established. The theory and method of adaptive control based on the MR damper for the long-span bridge and tall building structures are built, and the effectiveness and reliability of the adaptive control for the long-span bridge and tall building structures using the MR damper are verified through numerical simulation and model test. In addition, the theory and method of sub-structural damage identification for long-span bridge are derived, the influence of soil-structure dynamic interaction on the seismic isolation and control effects with different isolation and control measures and the damage responses and the sliding base-isolation of large structures under the excitation of underground explosion are investigated.
试验研究了形状记忆合金材料的力学性能,建立了SMA材料的本构模型;研制了一种SMA复合橡胶隔震支座,数值仿真分析了应用SMA复合橡胶支座的大跨桥梁和高层建筑结构的隔震效果,从而验证了SMA复合橡胶支座的自适应隔震性能及其震后自恢复能力;研制了一种SMA阻尼器,试验研究了SMA阻尼器的力学性能,建立了SMA阻尼器的恢复力模型,建立了基于SMA阻尼器的大跨桥梁结构自适应控制理论与方法,通过数值仿真与模型试验验证了大跨桥梁结构SMA阻尼器自适应控制的有效性与可靠性;研制了一种MRF-04K型磁流变阻尼器,试验研究了MR阻尼器的力学性能,建立了MR阻尼器的恢复力模型,建立了基于MR阻尼器的大跨桥梁和高层建筑结构的自适应控制理论与方法,通过数值仿真和模型试验验证了大跨桥梁和高层建筑结构MR阻尼器自适应控制的有效性与可靠性;还建立了大跨桥梁结构的子结构损伤识别的理论与方法,研究了土-结构动力相互作用对不同隔震和控制措施的减震控制效果的影响以及地下爆炸波作用下各类大型结构的灾害响应与滑移隔震。
-
In this thesis, I summarize the theoretical calculation method, applied scope and notice of siphonic drainage system, and point out the advantage of siphonic drainage system compared with gravitation drainage system. In the archetype experiment study of siphonic drainage tube, I adopt different tube diameter and different structural height to survey the drainage volume and press in different place. I observe various kinds of flow state, and get chief factors which influence hydraulic peculiarity of system as the tube diameter or structural height, and find out the relevance of factor to flux. I apply CFD Fluent software and adopt standard k-ε model and RNG k-ε model, then use finite volume method and second-order upwind scheme to discrete numerical model, while coupling numeration of velocity field and press is based on SIMPLE. In the numerical simulation of curved part of tube, siphonic drainage tube experiment system and multi-outlet siphonic drainage system, I make research on internal velocity and press of system in different project condition by changing the tube diameter of curved part, negative press value in tube export and improving the quantity of water gutter. This thesis first adopts a method of combining archetype experiment and numerical simulation to study the siphonic drainage system, test and verify the validity of experiment and numerical simulation, and makefurther study on system, it solves the problems of limited testing conditions, and has a logical results, it can provide a valid method for optimizing and designing the drainage tube-net system. The conclusion have referring value for study and design of siphonic drainage system.
本文首先对虹吸式排水系统理论计算方法、适用范围以及注意事项做出总结,并分析了虹吸式排水系统的优势;再对虹吸式排水管道进行原型试验研究,采用不同管径不同立管高度,对系统流量、管道压强进行量测,观察了各种工况下的流态,对其水力特性进行研究分析,找出影响水力特性的落差、管径主要因素以及与排水量的关系;进一步应用计算流体力学Fluent软件,采用标准κ-ε模型与RNGκ-ε模型,计算过程应用有限体积法和二阶迎风格式对数值模型进行离散,速度和压力的耦合采用SIMPLE算法,分别对系统弯管段、虹吸排水管道试验系统、多斗虹吸式排水系统进行数值模拟分析,通过改变管段弯头处半径、管段出口负压值、增加雨水斗数对不同工况下系统内部的速度和压力进行研究;本文首次采用结合原型试验与数值模拟相结合的方法,对虹吸式屋面雨水排水系统进行研究,试验与模拟相互验证,并进行拓展,很好地解决了虹吸式屋面雨水排水系统由于试验条件限制问题,结果正确合理,为排水管网系统设计和优化研究提供了有效的方法,对工程设计有较好的参考价值。
-
In order to overcome the defect of traditional methods and to find a new simply and effective time-domain method to eliminate the influence of boundary reflection. The main contents of studies and achievements are as follows: The liquefiable saturated sand dynamic character researches are conducted by means of the resonant column test and the dynamic tri-axial test; The undrain dynamic relationship between stress and strain, the damping ratio, saturated sand liquefaction mechanism, laboratory liquefaction standard, the effective factors of liquefaction are considered in laboratory. Liquefaction strength parameters used in element numerical simulation are obtained.
为克服传统方法存在的问题,寻求一种简单有效、能消除截断边界反射影响的时域有限元方法,本文主要开展了如下研究工作:对工程场地土体进行了标准贯入、静力触探、剪切波速等现场原位试验、室内动三轴试验以及共振柱试验,针对研究区域内可液化的饱和土进行了动力特性试验研究,分析了饱和土体的不排水动应力~应变关系和阻尼特性;对研究区域内的饱和砂土的液化机理,室内试验液化判别标准及影响饱和砂土液化的诸多因素进行了研究,得出了工程场地土体的抗液化强度指标等有限元模拟所需参数。
-
This article introduced one kind of use was mad-the solid two-phase flow related theory and the related heat transfer research trial result,establishes the process mathematical model,carries on the pa...
介绍一种利用气固两相流动有关理论及有关传热研究试验结果,建立过程数学模型,对气流干燥管进行分段,分区间逐次计算方法,其计算结果与实际情况吻合较好,并通过对直管与脉冲管的计算结果分析其优缺点,可以用于工程计算。
- 推荐网络例句
-
The split between the two groups can hardly be papered over.
这两个团体间的分歧难以掩饰。
-
This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.
这种做法不仅鼓励了更多的反应,而且减少跟风的可能性。
-
The new PS20 solar power tower collected sunlight through mirrors known as "heliostats" to produce steam that is converted into electricity by a turbine in Sanlucar la Mayor, Spain, Wednesday.
聚光:照片上是建在西班牙桑路卡拉马尤城的一座新型PS20塔式太阳能电站。被称为&日光反射装置&的镜子将太阳光反射到主塔,然后用聚集的热量产生蒸汽进而通过涡轮机转化为电力