Investigation of Fracture of Spheroplastics under Static and Dynamic Loading

An experimental study of static and dynamic fracture properties of a spheroplastic that has a matrix of polyester resin containing a filler of glass microspheres was conducted. Crack propagation was investigated under loading conditions generated by a pulse magnetic field. Microstructure features of dynamic fracture were analyzed.     

Investigation Into Static and Dynamic Performance of the Copper Trace Current Sense Method

This paper investigates the static and dynamic performance of current sense methods, which exploit the resistive voltage drop across the current carrying copper trace. This approach promises very low cost since no dedicated shunt resistor is required, no additional power losses occur and no extra space on the printed-circuit-board (PCB) is necessary. A microcontroller can be used to calibrate the copper trace resistance and implement a temperature drift compensation by means of a temperature sensor. Given that today almost every electronic device has at least one microcontroller that can provide the small computation power required for this current sensing technique, the additional cost of such a technique is small.      

Investigation of the precision in X-ray diffraction analysis of VCSEL structures

In principle, the structural components of a vertical cavity surface emitting laser, such as the alloy compositions, and the layer thicknesses, can be obtained from the exact fit of a simulated X-ray diffraction pattern to a measured diffraction pattern. In practice, because of the number of layer and thickness variables in a typical structure, it is unlikely that an exact fit can be achieved within a reasonable timescale. Rather a near fit is a more practical target along with a measure of the precision that a near fit can provide. This paper considers pragmatic strategies for data collection and simulation along with a realistic appraisal of the current capabilities for precision.     

高精度位移传感器动静态溯源和校准装置的研制

介绍了高精度位移传感器的动、静态特性溯源和校准原理及其标准装置的结构组成,并对它进行了实验验证.该装置可根据位移传感器在实际测量中的使用状态以及幅频响应范围,生成相应幅频下的标准动态信号并产生标准振动,经过同步采集及频谱分析,可得到在不同频率下相对激光基准的幅相误差.其生成的标准动态信号量值可直接溯源到激光波长,并可对位移传感器实现0～30 μm下的任意间隔的线性校准和1～100 Hz下的动态校准,它还可用于在线传感器的动静态特性的校准.     

基于绝对加速度完整反馈AMTMD的动力特性

本文进一步研究了作者提出的主动多重调谐质量阻尼器AMTMD的动力特性。基于结构和第j个ATMD绝对加速度的两个完整反馈模式(因为在实际中加速度传感器是测量绝对加速度)，讨论了AMTMD的动力特性。数值分析表明，在设计AMTMD时应选用基于结构绝对加速度的完整反馈模式。     

径向水润滑滑动轴承动静态特性的有限差分法分析

本文基于有限差分法利用MATLAB编程研究了轴承型式(圆柱轴承、椭圆轴承、三叶轴承)、水槽布置方式、长径比和半径间隙对水润滑轴承动静态特性的影响.结果表明,三种轴承中圆柱轴承的承载能力最强,但动态性能欠佳;三叶轴承的动态性能最好,但承载能力最差;椭圆轴承性能则介于两种轴承之间.且均布式水槽的数量越多,轴承的承载能力越低...     

Energy Absorption Characteristics of Dual Phase Steel Tubes Under Static and Dynamic Loading

Abstract: Thin walled tubes are used as energy absorbing elements in automobile applications. The circular tube proves to be a popular energy absorber because it provides a reasonably constant operating force which is the prime characteristics of the energy absorber. Square and rectangular tubes are widely used in automobile structures as these cross sections are suitable for welding with other components in the structure and hence highly preferred. Advanced high strength steels can be utilised to absorb crash energy and minimise intrusion in the occupant zone. In this work circular, square and rectangular tubes made up of dual phase steel are tested in static and dynamic conditions. All the tubes are subjected to same amount of input impact energy but the specific energy absorption is higher in circular steel tubes. The results are compared with those for annealed tubes of same cross section. The effect of impact velocity is also studied by keeping the impact mass constant and varying the drop height. The experimental results are compared with the theoretical results and good agreement is found.     

基于微波的管内气固两相动静特性的实验研究

本文首先根据气固两相流参数测量的特性搭建了气固两相流试验台,其中包括静态微波吸收试验台以及小型垂直气固两相流试验台;并且建立了一套基于虚拟仪器的试验数据采集和处理分析系统.然后,对在静态和动态情况下的微波信号吸收特性进行了试验研究,最后,通过对实验数据的分析,建立了相应的数学模型.     

94GHz TE02模回旋管Vlasov模式变换器的设计与模拟

该文研究并设计了一个由Vlasov阶梯型开口辐射器、椭圆面反射器和抛物面反射器组成的TE02模回旋管准光模式变换器。首先采用几何光学研究了阶梯型开口辐射器、椭圆面反射器和抛物面反射器的具体形状,再利用矢量绕射理论分析了其工作过程,最后结合94 GHz TE02模回旋管的具体参数,编写仿真程序详细讨论了工作模式在此模式变换器中的变换过程。模拟结果表明,94 GHz回旋管中的TE02模在输出窗处被转换为能量集中的准高斯波束,转换效率为78.35%。     

Research on Static and Dynamic Characteristics of the Damping Blade of the Blast Furnace Top Gas Recovery Turbine

A blast furnace top gas recovery turbine(TRT) device is affected by the force of steady-state flow and non-steady-state interaction so that the working-station is poor.A damper which is made of metal rubber is designed to improve stabilization of the blade of the TRT,and to reduce vibration of the TRT.The damping blade of the TRT is analyzed about its static stress and displacement,modal and transient in ANSYS.The results are contrasted.The result indicates that the damper can reduce inherent failure of the blade,and dynamic-stress.The structure of the damper is simple,and easy to be made.     

Investigation of the Structure of Polymer Networks from the Data on Dynamic Moduli at Different Static Deformations

Based on the previously developed molecular theory, we analyze experiments in which a small periodic deformation is applied to a statically extended elastomer and then the dynamic modulus is measured as a function of the static extension ratio . The dependence of the loss modulus on , which contains three parameters, is investigated, and what information on the network structure is contained in these parameters is elucidated. The accuracy of the information obtained is discussed with the use of the literature experimental data.     

Static and Dynamic Moduli of a Cold Recycled Emulsified Asphalt Mixture

Strength of Materials - The design of the pavement structure can make use of moduli to predict its performance during a preset lifetime. It is essential to study static and dynamic moduli...     

层状板岩动力破坏特性数值试验研究

为研究层理面数和冲击载荷对层状板岩动力破坏特性影响,利用LS-DYNA有限元软件模拟了层状板岩试件在不同冲击速度下的SHPB实验,再现了SHPB实验过程中的加载波形和层状板岩试件的破坏过程,模拟结果与实验结果吻合度较好。研究结果表明:层状板岩试件的耗散能量随层理面数的增加而增加,双层、三层和四层板岩试件相比单层板岩试件耗散能量的增长分别为0.2%、0.4%和1.87%;试件破坏开始于端面周边,滞后于应力峰值,当冲击速度为6.5 m/s时,层状岩石试件以轴向劈裂破坏为主,冲击速度为12 m/s和20 m/s时试件的破坏模式为轴向劈裂破坏、径向剪破坏和端面拉压破坏的混合破坏。     

Sol-gel生物活性玻璃体外矿化沉积的动态/静态体外模拟系统对比研究

采用溶胶-凝胶法制备了CaO-P2O3-SiO2系统生物活性玻璃粉体,并通过成型烧结工艺制成多孔材料,对比研究了样品在动态和静态2种体外模拟实验系统中的材料矿化沉积,通过测量溶液pH值,Ca^2 浓度,及样品的XRD、SEM、FTIR测试,证明了动态体外模拟系统可以更好地模拟体内环境,生物活性玻璃材料在2种模拟系统中表面都有碳酸羟基磷灰石生成。     

汽车发动机气门机构的动态特性分析

针对发动机配气机构,综合考虑气门挺杆、凸轮推杆、摇臂、摇臂轴、摇臂轴支承座以及气门杆的非刚性,建立四自由度的动力学模型.在受到推杆运动激励下,建立配气机构的动力微分方程,分析研究对系统固有特性和频率传递特性.研究结果可为气门机构的动态优化设计提供参考     

Static and Dynamic Tearing of Thin Steel Sheets

This paper presents the energy analysis of static mode III fracture of thin steel sheets. For dynamic tearing studies we used the Charpy test apparatus. Static tearing tests performed on three types of steel sheets indicate that the linear relationship of Mai and Cotterell is valid for specimens with a leg width W up to 30 mm. In the given range, the specific work of fracture _e is determined according to the Mai–Cotterell model. The _e kinetics is studied as a function of the sheet thickness B, radius of curvature , and loading rate V. The modified model includes a linear dependence of versus W. Moreover, we show that variation of the loading rate V from 1 to 300 mm/min has no effect on the specific work of fracture _e. A slight decrease in the dynamic fracture toughness J_0,d has been found.     

计算橡胶隔振器静态特性的数值分析方法

以橡胶隔振器为研究对象,利用有限元ABAQUS分析软件,进行了橡胶隔振器有限元建模的数值试验分析;为了能更精确的描述橡胶的特性,引用了多年来发展的几种弹性应变能函数方法,选取本构方程来拟合试验数据以作为ABAQUS软件对橡胶材料特性曲线的评估,寻找一种描述橡胶特性的最佳的方法。预测的计算结果与试验吻合较好,表明所建的数学模型和有限元计算方法能较理想的获得橡胶隔振器静态解。