查询词典 span loading

It introduces a kind of novel loading test system, based on the operation principle of damper. this loading system is operated by the driving motor. it realizes the loading, in that the damper has a negative drive force that puts on the motor. Based on the ordinary electromagnetic damper, the thesis presents a novel hybrid excitation electromagnetic damper which has adjustable work characteristic, analyses the working principle and structural feature of the electromagnetic damper, deduces the formulas to calculate the eddy current density through the Electromagnetic theory, analyses the distribution of the eddy current in the cotyloid rotor, and also studies the method of calculating the damp torque, establishes the mathematical model of the electromagnetic damper, analyses the relationship between the electromagnetic damper structural parameter and damp torque, researches the engineering design and analysis method of the electromagnetic damper, provides theory foundation for the design and analysis of the electromagnetic damper, contrives a hybrid excitation electromagnetic damper that satisfies the target request, designs a set of compound excitation electromagnetic damping loading control system whose control core is AT89C51 monolithic integrated circuit, analyses the electric circuit part, and carries on the experimental test to this set of electric circuits. Finally it debugs this electromagnetic damping loading system, this system satisfies the target request proposed.

论文提出了一个全新的加载测试系统种类，该加载系统是在阻尼器工作原理基础上，利用电动机拖动阻尼器运转，从而阻尼器产生一个与运动方向相反的阻尼力矩，该力矩作用在电动机上实现对电动机加载测试；同时，论文在一般电磁阻尼器基础上提出了一种新型的可调式复合励磁电磁阻尼器结构，该种阻尼器的工作特性在一定范围内可进行调节；论文分析了电磁阻尼器的工作原理和结构特点，运用电磁场理论分析推导了电磁阻尼器的涡电流密度公式，分析了涡电流在转子杯内的分布图，并对阻尼力矩计算方法进行了研究，建立了电磁阻尼器的数学模型，分析了电磁阻尼器结构参数和阻尼力矩之间的关系，对电磁阻尼器的设计和分析方法进行了研究，为电磁阻尼器的工程设计建立了理论基础；设计了满足技术指标要求的复合励磁电磁阻尼器和一套以AT89C51单片机为控制核心的复合励磁电磁阻尼加载控制系统，对该控制系统硬件电路各部分进行了分析和设计，对软件进行了设计，并对控制电路进行了试验调试，该系统满足所提出的加载指标要求。

The design mains design about the loading-machine department of continuous-type caterpillar band coal-loading machine, the loading department uses the spider loading, the transportation system uses the scraper conveyer, the loading department and the department of transportation uses in common a group of oil motor to actuate, to take the place of the reduction gear, which makes the machine structure to be more compact and the revolution to be more coordinated, reduced the breakdown.

本设计是对连续式履带装煤机的装运部进行设计，装载部采用的是星轮装载，运输系统采用刮板输送机，装载部和运输部共用一组液压马达驱动，取消装载减速器，使机器结构更加紧凑，运转更加协调，减少了故障。

And tonight is my first time on c-span, which is a channel i obviously always watch when i couldn"t stand the sensationalism and demagoguery of pbs and qvc. if i still couldn"t fall asleep after watching c-span, there is c-span 2 and c-span 3. thank you very much.

今晚是我第一次来到c-span频道，通常当我无法忍受pbs和qvc的鼓吹与煽动时我就会选择看你们的频道（pbs的节目以主观著称，qvc则是购物频道，说这段的时侯镜头给了下面人一个特写，莫非是这两个频道的老板？

The stretching influence on the near trusses should be considered when using the stretching-twice method, and the construction is hard to be controlled. The Harbin exhibition sports center with a 128m support span, attached to a deep design calculation of the super-large span prestress truss string structure, stretching once in tension bed method is brought forward for the bottom cable of the single truss string structure. From calculation research on the friction force between the tension bed and the truss string structure, the friction influence is considered for the displacement method of the middle of span, with the action of the fixed cable stress. This method, with vertical displacement of the middle of span as its main control target for prestress stretching, is successfully applied in the prestress stretching construction of the project.

二次张拉需考虑张拉对相邻桁架的影响，施工控制难度大，本文结合哈尔滨会展体育中心支座跨度128m的超大跨度预应力张弦桁架结构的深化设计计算，提出了单榀张弦桁架下弦拉索胎架一次张拉法施工方法，通过对张拉阶段胎架与张弦桁架间摩擦力的计算研究，定量索力下跨中位移法考虑摩擦力影响，以跨中竖向位移作为预应力张拉的主要控制指标，成功地完成了该工程预应力张拉施工。

With the appearance of a free span pipeline, its loading types and stress state will be changed. Especially when ocean currents pass through it, a periodical vortex shedding is often produced and induces vibration of the free span pipeline. This type of vibration contributes a lot to the fatigue failure of a free span pipeline.

管跨段的出现改变了海底管线所承受的载荷形式和应力状态，尤其是在海流作用下流经管跨时，常伴随着周期性的涡旋发放，引发管跨段的周期性振动，成为管跨段发生疲劳失效的主要因素之一。

Such parameters as the percentage of ordinary reinforcment, amounts and configuration of unbonded prestressed tendons, the ratio of span to depth and the loading patterns were considered. Based on the results, the fomula for the eqivalent length of deformation zone on the beams at ultimate were developed. A simple formula was developed for the ultimate mid-span deflection of concrete beams with concept of equivalent length of deformation zone, and the deformation of beam before internal reinforcement yielding was predicted by the traditional formula for the deformation of partically prestressed concrete beam. Then an analytical model was deduced for analyzing the ultimate stress increment in those concrete beams prestressed with external or internal unbonded tendons based on the mid-span deflection.(4) Testes were carried out on a thin-walled concrete box beam presressed with external CFRP tendons to study its short-term performances under uniform load, long-term behaviors under uniform load, and full-time performance under four-point load in turn.

3以体内非预应力钢筋配筋率、体外预应力筋配筋率、体外预应力筋布置形式、预应力度、跨高比、荷载形式等为参数，用非线性分析程序对体预应力筋混凝土梁进行了参数分析，依据分析结果提出了以综合配筋指标和预应力度为参数的等效变形区长度的计算公式，进而提出了基于等效变形区长度的极限挠度计算公式；体内非预应力钢筋屈服前的挠度计算采用常用的部分预应力混凝土梁挠度计算公式；依据试验和非线性数值计算结果，将不同转向块布置形式的体外预应力混凝土梁简化为跨中一个转向块的体外预应力混凝土梁，推导了基于跨中挠度的体外预应力筋应力增量的简化计算公式。

Such parameters as the percentage of ordinary reinforcment, amounts and configuration of unbonded prestressed tendons, the ratio of span to depth and the loading patterns were considered. Based on the results, the fomula for the eqivalent length of deformation zone on the beams at ultimate were developed. A simple formula was developed for the ultimate mid-span deflection of concrete beams with concept of equivalent length of deformation zone, and the deformation of beam before internal reinforcement yielding was predicted by the traditional formula for the deformation of partically prestressed concrete beam. Then an analytical model was deduced for analyzing the ultimate stress increment in those concrete beams prestressed with external or internal unbonded tendons based on the mid-span deflection.(4) Testes were carried out on a thin-walled concrete box beam presressed with external CFRP tendons to study its short-term performances under uniform load, long-term behaviors under uniform load, and full-time performance under four-point load in turn.

3以体内非预应力钢筋配筋率、体外预应力筋配筋率、体外预应力筋布置形式、预应力度、跨高比、荷载形式等为参数，用非线性分析程序对体预应力筋混凝土梁进行了参数分析，依据分析结果提出了以综合配筋指标和预应力度为参数的等活动房效变形区长度的计算公式，进而提出了基于等效变形区长度的极限挠度计算公式；体内非预应力钢筋屈服前的挠度计算采用常用的部分预应力混凝土梁挠度计算公式；依据试验和非线性数值计算结果，将不同转向块布置形式的体外预应力混凝土梁简化为跨中一个转向块的体外预应力混凝土梁，推导了基于跨中挠度的体外预应力筋应力增量的简化计算公式。

The instructive conclusion was: 1 under the vertical loading, the shear-lag effect was produced badly, more severer under concentrated loading than under uniform loading .2 the longitudinal bending deformation of the beam flange was true of the imitating plane assumption of deformation . 3 the width length ratio was confirmed as the first factor working on the shear-lag effect among all the geometric parameters;4 the shear-lag coefficient of simple-supported box-girder was severer than the continuous box-girder, the shear-lag effect in the inner supported section of continuous beam was much more severer, we need paying more attention for it in designing. 5 the non-liner characteristics of material deformation have littlie influence on shear-lag effect in BGCW. 6 the experiential calculating formulation and calculating diagram for the effective flange width was raised with the only factor of the width-span ratio., but the primary location of axis of bending moments should not be changed while calculating the inertial moment .

研究认为：1室内模型试验和空间有限元分析结果均表明波形钢腹板组合箱梁在竖向荷载作用下，翼板出现了典型的纵向应力剪滞效应。2在竖向荷载作用下，截面高度上各点纵向正应变分布认为可符合"拟平截面假定"，以此作为波形钢腹板组合箱梁抗弯计算的基本假定。3箱梁宽跨比是影响波形钢腹板组合箱梁翼板剪滞效应的主要因素。4连续波形钢腹板组合箱梁的翼板剪滞系数大于简支梁，且连续箱梁内支点截面翼板剪滞效应相当严重，对此需十分重视。5当混凝土翼板受力由弹性阶段进入弹塑性阶段时，材料的非线性特性对翼板的剪滞效应影响甚微。6提出了根据组合箱梁的宽跨比参数来计算翼板有效宽度比的经验公式和计算图表，但箱梁截面抗弯惯性矩的计算不应改变原先的截面中和轴位置。

On the base of fatigue loading spectrum achievements, combining the characteristics of large-span grid structure with hanging cranes and the using-requirement on fatigue loading spectrum of grid structure with hanging cranes, this paper has firstly put forward the theoretic method for constructing fatigue loading spectrum of grid structure with hanging cranes, organized the relevantprogram--GJFLS. and elementally established the program loadingspectrum .

在继承疲劳载荷谱已有成果的基础上，本文结合网架设置悬挂吊车的特点以及网架疲劳载荷谱的使用要求，首次提出了网架疲劳载荷谱编制的理论方法，并编制了相应的程序，初步建立了网架程序载荷谱。

By calculating the equivalent loading,the process of strength degradation under random loading was transformed into a process under the deterministic loading,and the relationship between reliability andtimes of loading action was obtained.Besides,the time-dependent reliability models under multi-loadings were established by analyzing the relationship between action times of different loadings and time.

该模型通过计算当量载荷，将随机载荷作用下的强度退化过程等效为确定性载荷作用下的退化过程，得到零件可靠度与载荷作用次数的关系，在此基础上，通过分析不同载荷出现次数与时间的关系，得到多个载荷共同作用下零件可靠度随时间的变化规律。

In the days of sailing vessels the crew were afraid they would be becalmed on the ocean.

在使用帆船的时代，船员们担心他们会因为无风而无法在海洋上航行。

As long as foreign donors pay the PA's salary bill, few expect a new intifada.

只要外国继续为巴权力机构的薪水买单，希望发动新暴动的人便寥寥无几。