基于形状变量和全局响应面法的增压器涡轮多目标优化

应用HyperMesh软件中HyperMorph模块的网格变形功能创建了增压器涡轮8个形状变量。为减少计算量,运用试验设计(DoE)分析方法对形状变量进行筛选,去掉1个对体积、最大应力和最大变形影响都不显著的因子。针对筛剩的7个变量,利用HyperStudy中的全局响应面法(GRSM)对涡轮进行了多目标优化,得到了涡轮体积和最大形变量之间的帕雷托边界。帕雷托边界表明:当体积属于[5 400,5 700]mm3区间时,增加涡轮体积与减少最大形变量具有明显的相关性;当体积大于5 700mm3时,继续增加体积对减小最大形变量无明显作用。形状变量、涡轮体积与形变量的蛇形关系图表明:体积为较小值时,形变量均较大;最大形变量为较小值时,体积依然有可能取较小值。研究方法与结论为增压器涡轮的优化设计提供了指导,具有一定的工程应用价值。

一类双输入非线性系统的二维平面形状合同控制器设计

针对一般控制系统,利用微分几何中的曲线理论提出了形状变量、被控形状轨迹曲线和形状合同控制等概念.然后,针对一类具有双输入及二维形状变量的非线性系统,利用相对曲率概念和曲线论基本定理设计了二维平面形状合同控制器,这种形状合同控制器能够保证系统的被控形状轨迹曲线与参考轨迹曲线具有完全相同的形状.最后的仿真说明了所采用方法的有效性.

车门结构多目标轻量化研究

针对现有结构多目标轻量化设计采用单一变量(如板件厚度为优化变量)的不足,将网格变形技术创建的形状变量引入到了车门结构多目标轻量化设计中,建立了以板件厚度与车门结构形状同时作为设计变量的参数化有限元模型。对该车门进行了动态试验测试,验证了有限元模型及计算结果的可靠性;考虑到该车门一阶频率过低的问题,将一阶频率最大、车门质量最小作为优化目标,垂向刚度、窗框刚度为约束,进行了试验设计(DOE),通过Kriging函数模型拟合了要优化的目标及约束,经过精度校验,验证了该近似函数模型符合精度要求;最后利用多目标遗传算法进行了寻优计算。研究结果表明:在垂向刚度、窗框刚度满足约束值的情况下,车门质量最终降低2.84 kg(减重达13%),一阶频率提高了25.8 Hz。

Shape Optimal System for Linear Elastic Structures

An integrated system FSOP2D,including modules for the shape optimal modeling,structural analysis,sensitivity analysis,optimal method library and post- processing,is developed.By selecting fictitious loads as the design variables that has a linear relationship with the grid point locations and using design sensitivity analysis of the domain method,it is easier to solve the velocity field.In the course of optimal iterations,mesh distortion is kept to a minimum,sensitivity derivatives of object function,stress constraints and displacement constraints are derived.Computation of sensitivity analysis is achieved in the system.Two engineering examples are used to prove the system's effectiveness,the optimal results can successfully be obtained by lesser number of iterations.

Multipartite State Representations in Multi-mode Fock Space and Their Squeezing Transformations

We present the continuous state vector of the total coordinate of multi-partlcle and the state vector of their total momentum, respectively, which possess completeness relation in multi-mode Fock space by virtue of the integration within an order product （IWOP） technique. We also calculate the transition from classical transformation of variables in the states to quantum unitary operator, deduce a new multi-mode squeezing operator, and discuss its squeezing effect. In progress, it indicates that the IWOP technique provides a convenient way to construct new representation in quantum mechanics.

Relationship between the rock mass deformation and places of occurrence of seismological events

Static effort of rock mass very rarely causes of rock burst in polish coal mines. Rock bursts with source in the seismic tremor within the roof rock layers are prevailing. A seismic tremor is an effect of rupture or sliding in roof layers above the exploited panel in coal seam, sometime in a distance from actual exploitation. Sliding, as a rule occurs in fault zone and tremors in it are expected, but monolithic layer rupture is very hard to predict. In a past few years a practice of analyzing state of deformation in high energy seismic tremors zones has been employed. It let gathering experience thanks to witch determination of dangerous shape of reformatted roof is possible. In the paper some typical forms of roof rocks deformations leading to seismic tremor occurrence will be presented. In general these are various types of multidirectional rock layers bending. Real examples of seismic events and rock bursts will be shown.

Form Invariance and Conserved Quantity for Non-holonomic Systems with Variable Mass and Unilateral Constraints

The paper studies the form invariance and a type of non-Noether conserved quantity called Mei conserved quantity for non-holonomic systems with variable mass and unilateral constraints. Acoording to the invariance of the form of differential equations of motion under infinitesimal transformations, this paper gives the definition and criterion of the form invariance for non-holonomic systems with variable mass and unilateral constraints. The condition under which a form invariance can lead to Mei conservation quantity and the form of the conservation quantity are deduced. An example is given to illustrate the application of the results.

Influence of Quantal and Statistical Fluctuations on Phase Transitions in Finite Nuclei

Investigations on thermal evolution of pairing-phase transition and shape-phase transition in light nuclei are made as a function of pair gap, deformation, temperature and angular momentum using a finite temperature statistical approach with main emphasis to fluctuations. The occurrence of a peak structure in the specific heat predicted as signals of the pairing-phase and shape-phase transitions are reviewed and it is found that they are not actually true phase transitions and it is only an artifact of the mean field models. Since quantal number and spin fluctuations and statistical fluctuations in pair gap, deformation degrees of freedom and energy when incorporated, it wash out the pairing-phase transition and smooth out the shape-phase transition. Phase transitions due to collapse of pair gap and deformation is discussed and a clear picture of pairing-phase transition in light nuclei is presented in which pairing transition is reconciled.

Reducing Numerical Oscillations through Modified Circuits for Inclusion of Frequency Influence in Transmission Line Representation

In this article, a transmission line is represented by a cascade of n circuits using a single phase. It is analyzed what is the reasonable number of n circuits and the number of blocks composed by parallel resistor and inductor in parallel for reduction of numerical oscillations. It is simulated the numerical routine with and without the effectof frequency in the longitudinal parameters. Initially, it is used to state variables and 7t circuits representing the transmission line composing a linear system which is solved by numerical routines based on the trapezoidal rule. The effect of frequency on the line is synthesized by resistors and inductors in parallel and this representation is analyzed in details. It is described as transmission lines and the frequency influence in these lines through the state variables.

Dual mean Minkowski measures of symmetry for convex bodies

We introduce and study a sequence of geometric invariants for convex bodies in finite-dimensional spaces, which is in a sense dual to the sequence of mean Minkowski measures of symmetry proposed by the second author. It turns out that the sequence introduced in this paper shares many nice properties with the sequence of mean Minkowski measures, such as the sub-arithmeticity and the upper-additivity. More meaningfully, it is shown that this new sequence of geometric invariants, in contrast to the sequence of mean Minkowski measures which provides information on the shapes of lower dimensional sections of a convex body, provides information on the shapes of orthogonal projections of a convex body. The relations of these new invariants to the well-known Minkowski measure of asymmetry and their further applications are discussed as well.

Supersymmetry and SWKB Approach to Dirac Equation with Hyperbolic Scarf Potential

By using the supersymmetric quantum mechanics and shape invariance concept, we study the Dirac equation with the hyperbolic Scarf potential and the exact energy spectrum is obtained. Also, we calculate the bound state energy eigenvalues by using the supersymmetric WKB approximation approach so that we get the same results.

Spontaneous Fission Barriers Based on a Generalized Liquid Drop Model

The barrier against the spontaneous fission has been determined within the Generalized Liquid Drop Model （GLDM） including the mass and charge asymmetry, and the proximity energy. The shell correction of the spherical parent nucleus is calculated by using the Strutinsky method, and the empirical shape-dependent shell correction is 6mp10yed during the deformation process. A quasi-molecular shape sequence has been defined to describe the whole process from one-body shape to two-body shape system, and a two-touching-ellipsoid is adopted when the superdeformed one-body system reaches the rupture point. On these bases the spontaneous fission barriers are systematically studied for nuclei from 2a^Th to 249 Cm for different possible exiting channels with the different mass and charge asymmetries. The double, and triple bumps are found in the fission potential energy in this region, which roughly agree with the experimental results. It is found that at around Sn-like fragment the outer fission barriers are lower, while the partner of the Sn-like fragment is in the range near l^SRu where the ground-state mass is lowered by allowing axially symmetric shapes. The preferable fission channels are distinctly pronounced, which should be corresponding to the fragment mass distributions.

New data processing method for improving the measurement accuracy in FTP

During the 3D shape measurement,there are noises in the images that are obtained by the capture system.The traditional method,Fourier transform profilometry(FTP) technique,improves the accuracy only by the filtering method in the frequency domain.In this paper,the curve fitting method is used for the light field distribution calculation before the filtering process applied in the frequency domain by choosing a suitable filter window,and then the higher quality of the basic frequency component signal is got.This method can avoid the frequency overlapping caused by the noise,so the improvement of the measuring accuracy of FTP is realized.

Structure Evolution in the Even-Even ^124-134Xe with IBM2

We have investigated the structure evolution of the ^124-134Xe isotopic chain in the framework of the proton-neutron interacting model IBM2. The positive parity spectra of the ground state, quasi-β and quasi-γ bands are reproduced well. The staggering in ^124-130Xe are almost completely removed and the ？ band agree well with the experiment data, even for the high-spin quasi-3 states. The key quantities of the collective structure evolution, including level energies, the B（E2） transition branching ratios, and the M1 excitations to 11^＋ mixer-symmetry states are analyzed by comparing with the experimental data. The parameters for representation of the Oπν（6） and SUπν^＊（3） features in isotopes are examined. Both experimental data and theoretical results show that the shape phase transition of ^124-134Xe isotopic chain is from the SUπν^＊ （3） （triaxial rotation） to the Uπν（5） （vibration motion） with a considerable constituent of the Oπν（6） symmetry （γ-unstable rotation）, where the shape phase transition rapidly takes place between the neutron number N = 76 and N = 78.

Generalized Coherent States for Position-Dependent Effective Mass Systems

A generalized scheme for the construction of coherent states in the context of position-dependent effective mass systems has been presented. This formalism is based on the ladder operators and associated algebra of the system which are obtained using the concepts of supersymmetric quantum mechanics and the property of shape invariance. In order to exemplify the general results and to analyze the properties of the coherent states, several examples have been considered.