整舱浮筏隔振系统功率流理论与试验研究

采用FEM和SEA方法计算整舱浮筏隔振系统传递的功率流，初步分析整舱浮筏隔振系统功率流传递特性。用间接方法测量了整舱浮筏隔振系统的功率流传递，分析整舱浮筏功率流理论计算和试验结果之间的关系及功率流的传递规律，说明采用FEM＋SEA方法计算整舱浮筏隔振系统的功率流隔振效果在工程上是可行的。     

基于柔性基础的双层隔振系统概率灵敏度分析

对基于柔性基础的双层隔振系统的功率流传递特性进行了分析，利用有限元分析软件ANSYS计算了传递到基础的功率流，并用概率灵敏度分析方法研究了功率流对隔振系统给定参数的灵敏度，为双层隔振系统的优化设计奠定了基础．     

一类复杂系统的功率流传递特性及其主动控制

综合考虑工程实际中多激励,多支承机组的柔性安装问题,建立了主被动复杂柔性隔振系统的统一动力学模型,将导纳方法推广到主动隔振分析中,采用了子结构导纳综合法对弹性板基础上主动隔振系统的传递功率流进行了分析,并从插入损失的观点探讨了功率流的主动控制策略,揭示了含有主动作动元件的柔性耦合系统的功率流传递机理。     

浮筏隔振系统多维耦合振动特性分析

针对工程中的浮筏隔振装置,建立了柔性基础上复杂激励多维耦合隔振系统动力学模型。考虑隔振支撑多维波动效应,运用子结构导纳法推导了耦合系统动态传递方程及功率流表达式,给出了系统的功率流谱。数值模拟计算表明,复杂激励隔振系统在低频域出现多个共振峰,在高频域基础的弯曲共振模态及隔振器驻波效应使得系统功率流提高。减小隔振器刚度能明显降低系统功率流但也使驻波效应提前。增加筏体质量可明显降低系统功率流。     

浮筏隔振系统的传递功率流研究

针对实际工程中浮筏装置的隔振性能评估,推导了一种用于浮筏隔振系统传递功率流计算的新方法,并利用本方法进行实例计算,预测各子系统联接界面或耦合点的功率流,描绘各耦合界面的传递功率谱。分析浮筏安装非对称性、机组振幅比对传递功率流的影响。     

吸振器在浮筏隔振系统中的应用

针对工程中广泛应用的浮筏隔振装置,建立柔性基础复杂激励作用下多维耦合浮筏隔振系统的动力学模型。由于浮筏隔振系统在低频范围内减振效果欠佳,为改善浮筏隔振系统的隔振性能,把吸振器引入到浮筏系统。利用子结构导纳综合法分别建立带有动力吸振器、自调谐吸振器和主动式自调谐吸振器的浮筏隔振系统动力学模型。以功率流为指标,研究单频激励下吸振器对浮筏系统功率流传递特性的影响。最后分析多频激励下带有自调谐吸振器的浮筏隔振系统的功率流传递特性。以传递到基础的功率流为目标函数,分析主动式自调谐吸振器在多频激励下的减振效果。仿真结果表明,吸振器对浮筏具有良好的低频隔振效果,吸振器类型不同与安装方式不同对传递到基础的功率流有不同程度的抑制效果。     

复杂结构安装频率对传递功率流影响

针对工程实际中弹性浮筏复杂隔振系统 ,建立了柔性基础上机组多扰源弹性浮筏耦合隔振系统动力学普遍模型 ,给出了系统动态特性结构化分析方法。根据工程中两机组浮筏隔振系统功率流数值计算结果 ,着重探讨了复杂结构安装频率及隔振器阻尼对支承结构柔性及传递功率流影响     

多源激励下浮筏隔振系统导纳功率流研究

建立了浮筏隔振系统的振子力学统计分析模型，使用导纳功率流的方法研究了隔振系统的振动响应和振动功率流特性，并通过数值方法分析了筏体和隔振器参数变化对传递到基础结构功率流的影响。分析结果表明：增大基础厚度、减小系统中耦合元件的耦合刚度和增大筏体质量可以有效控制系统的传递功率流。     

复杂弹性耦合隔振系统建模及其优化设计

复杂弹性耦合隔振系统是在多层隔振系统中考虑中间筏体和基础的弹性而形成的一类隔振系统，提出了关于这类复杂隔振系统子结构建模的新方法，并用该方法建立了二维复杂弹性耦合隔振系统的动力学方程。并在此基础上进一步提出了一种新的基于小生境的自适应遗传优化算法，运用该算法对二维复杂弹性耦合隔振系统基于系统功率流传递的最优化设计。     

主动隔振系统中功率流的最优化控制策略

用功率流指标描述主动隔振系统中能量的传输,以传轾到接受体的功率流量小为最优化控制目标,推导主动隔振系统中功率流传递的最优控制表达式,提出了ＳＭＲ主动隔振模型基于功率流的最优化控制策略。针对工程实际中的柔性安装问题,对四边简支矩形薄板的主动隔振进行了研究。     

A Thermally Shocked Unit Cell of a Fibre-reinforced Composite Material including interface cracks

The influence of a crack at the interface between the fibre and the matrix of a thermally shocked composite material has been considered theoretically. The time-dependending crack extension force has been calculated. A glass-aluminium composite is compared with a SiC? Al-composite.     

Hardenability: an alternative to the use of grain size as calculation parameter

Several austenizing treatments carried out on different types of quench-temper and carburizing steels confirm the relationship which exists between austenitic grain size and the treatment time and temperature parameters. A relationship has been established between the three variables, a regression plane linking them being obtained. A mathematical model is proposed which permits the treatment parameterP to be calculated theoretically, and making it possible to obtain from only chemical composition and austenizing temperature the data required to obtain the Jominy curve. The experimental results for diverse steels and the resulting structures agree with those obtained theoretically. A calculation programme has been developed in accordance with the model we present for both manufacture and quality control. Its industrial use has been widely verified.     

Dimensioning of a Fibre-Reinforced Composite under Thermal Loads in view of interface cracks

The influence of the variation of the fibre radius on the thermo-shock resistance has been calculated analytically. A glass fibre and a Sic-fibre embedded in an aluminium matrix are compared. The radius yielding maximal crack extension forces for an interface crack between the fibre and the matrix has been calculated theoretically.     

Packing of irregular particles

The packing of narrow fractions of irregular particles to a given density has been studied theoretically and experimentally. The equations given in Furnas' classical investigation have been altered to give more commonly valid expressions. It has also been found necessary to propose a new model, which better meets the experimental demands. An example is given of how to solve a multicomponent system by using this model.     

Stability of a crystal surface in fractional crystallization on a band

The problem on the morphological and thermal stability of a crystal surface in fractional crystallization on a band has been investigated theoretically. A model to describe the dynamics of the development of a striped perturbation of the crystal surface is suggested. It is used as a basis for analyzing the influence of the main factors on the stability, and a stability criterion has been derived. It has been established theoretically that the thermal instability must appear at small Reynolds numbers (Re < 10). Numerical experiments have shown that an increase in the length of the band, its inclination angle, as well as a decrease in the rate of melt feed and in the band motion velocity increase the thermal instability. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 82, No. 1, pp. 106–113, January–February, 2009.     

Depth of penetration of solid- or liquid-phase particles in opposing gas-suspension jets

The depth of penetration of particles in systems of opposing gas-suspension jets has been investigated theoretically and experimentally.     

Self-organization and electrooptical characteristics of a nematic liquid crystal-cellulose diacetate composite

Stable self-organization process has been observed during the formation of thin films of a composite based on a nematic liquid crystal and a cellulose acetate polymer matrix. Optical transmission characteristics and electrooptical response time of the composite have been theoretically calculated and experimentally studied.     

Influence of two-dimensional convection on solidification of back-tapered ingots

The influence of two-dimensional convection on the rate of solidification of a flat-shaped ingot in a wedge mold has been studied theoretically. The appearance of three crystalline zones in a solidified ingot is explained.     

Kinetics of Nucleus Growth from a Nanophase

Technical Physics Letters - The kinetics of nucleus growth from a parent nanophase medium with a limited stock of material has been theoretically studied in the presence of possible growth arrest...     

Three-dimensional analysis of magnetic field distortion of ferromagnetic beam-plates by the boundary element method

Magnetoelastic buckling of a ferromagnetic beam-plate has been experimentally and theoretically studied by many investigators. A great discrepancy between the experimental results and the theoretical predictions has stimulated related studies. It has been supposed that the discrepancy could be attributed to the finite size of the test piece; this case has not yet been solved exactly, or even numerically. In this study the boundary element method is applied to solve for the magnetic field distribution around the finite specimen.