查询词典 structural engineering

Firstly, this paper investigated roundly the basic theory of the ambient vibration method, analyzed systematically the main methods of ambient vibration identification, and discussed their advantages and disadvantages. Then we established the finite element model of structural dynamics and test model and analyzed their mutual relation, improved MUSIC method and correlation function method in the harmonic identification, and gave the subspace method and correlation function method based on continuous model, which is multi-harmonic retrieve technique. And then, this paper also puts forward least-squares method to estimate directly structural physical and modal parameters; this approach replaced the derivative operator in the continuous time model with an equivalent approximation, and estimated the physical parameters of structures by the least-squares method. And then, we discussed the approximation methods of derivative and their convergence. Finally, this paper researched the modal parameters of a frame structure by the simulation and test. The results demonstrated that subspace method, correlation function method and the least-squares method are effective and stable respectively.

全面地研究环境振动识别方法的基本理论，系统地分析环境振动识别方法的主要方法，讨论它们的优点和不足；建立结(来源：6666AB44C论文网www.abclunwen.com)构动力学的有限元模型和试验模型，分析有限元模型与试验模型之间的相互关系；改进谐波识别中的MUSIC识别方法和相关函数识别方法，给出大型结构模态识别的连续型的子空间分解识别方法和相关函数识别方法，这个方法是多元谐波识别方法；提出直接识别结构的物理参数和模态参数的最小二乘方法，这个方法利用导数的近似值代替导数值，并运用最小二乘方法识别结构的物理参数，讨论导数近似值的选择方法，分析算法的收敛性；通过仿真计算和模型实验，研究高层框架结构的模态参数识别，验证子空间分解识别方法、相关函数识别方法和最小二乘识别方法的有效性，算法的稳定性；从理论和试验两个方面分析和研究噪声对识别精度的影响，影响识别精度的因素，以及部分模态成分的模态参数不能够被识别的原因。

A four\|node piezoelectric composite laminated plated element was implemented for dynamic analysis of adaptive structure. The damping ratios of truncated models were considered as the control objects, so that each of the structural modal oscillation could decay rapidly. Hence, the structural oscillation was effectively controlled.

利用四节点压电复合材料层合板单元进行自适应结构的有限元动力分析；采用模态控制方法，将结构的各阶模态的阻尼比作为控制目标，并以此计算出各压电片的控制电压，达到控制结构振动的目的。

The origin、 development and present state of the container ship2. The deformation characters and collapse mode of the container ship3. The basic theory of thin-walled structural mechanics: The bending of the thin-walled beam; The unconstrained torsion of the thin-walled member bar; The constrained torsion of the thin-walled member bar with opening; The constrained of the thin-walled member bar with closed port.4. The calculation of the warp stress in the container ship based on the thin-walled structural mechanics theoryModeling of the hull ladder calculation based on referred mechanics theories of thin-walled member bar, calculation of crankle character of the each section, such as sectional coordinates、 Free twist shear flow、 secondary shear flow、 bend shear flow and so on.

本文主要包括下述六个方面的内容： 1 集装箱船的起源、发展和现状 2 集装箱船变形特征和破坏形式 3 薄壁结构力学的基本理论◇薄壁梁的弯曲；◇薄壁杆件的自由扭转；◇开口薄壁杆件的约束扭转；◇闭口薄壁杆件的约束扭转 4 利用薄壁结构力学理论计算集装箱船的翘曲应力建立船体阶梯计算模型，利用薄壁杆件力学中相关理论，求解各断面单元的弯扭特性，包括：扇性坐标、自由扭转剪流、二次剪流、弯曲剪流等。

In the present study, Hartree-Fock and Density Functional Theory with different basis sets were employed to calculate the structural and thermodynamic parameters of 66 thiophenyl, phenyl sulfoxide and phenylsulfonyl cycloalkane carboxylates. With the statistic software SPSS11.5 for windows and GQSARF2.0, the QSAR models relating physicochemical properties of these compounds to their structural and thermodynamic parameters were successfully obtained, using multiple stepwise regression method. The physicochemical properties observed in this work include octanol/water partition coefficient, chromatographic capacity index, toxicity (EC50 and LC50), and solubility etc.

本文采用从头算方法中的Hartree-Fock 方法、密度泛函理论方法(Density functional theory，简称DFT)中的不同基组，计算了苯硫基、苯亚砜基和苯砜基含硫芳香羧酸酯三类共66 个化合物的结构参数和热力学参数，利用SPSS11.5 for windows 统计软件和GQSARF2.0 软件，采用多元逐步回归法拟合得到与溶质-溶剂相互作用有关的物理化学性质与结构参数和热力学参数之间的QSAR 方程，这些物理化学性质包括辛醇/水分配系数、色谱容量因子、毒性(EC50和LC50)、溶解度等。

Although the research on the biophysical properties, genomic structural analysis and Cytopathology of the virus have been accomplished, the function of structural protein and the molecular mechanism of its infection are still unknown in case of the absence of the stable cell model of PfDNV infection in vitro.

但长期以来，由于缺乏稳定的PfDNV体外感染的细胞模型，PfDNV结构蛋白的功能及其复制侵染的分子机理仍不清楚。

The structural evolution properties of transition metal clusters containing from 13 to 60000 atoms are investigated by means of the Gupta potential combined with the steepest descent method. Four typical structural motifs are considered: icosahedron, decahedron, face centered cubic octahedron, and hexagonal close-packed.

采用Gupta原子间相互作用势结合最速下降法，对四种典型几何结构：Ih、Dh、Fcc-oct及Hcp，研究了尺寸介于13到60000个原子之间的同族元素Co、Rh与Ir团簇的结构演化特性。

One is based on the structural difference,and the other is based on the structural difference and multiple sequence alignment.

同时，本文提出了两种RNA有害突变预测的方法，一种是基于结构差异的方法；另外一种是基于结构差异与多序列序列比对的方法。

It was shown that the structural parameter was strongly affected by the diameter and depth of tunnels. The structural parameter in vault direction decreased firstly and then increased along with the tunnel depth.

研究得出：围岩的结构性参数与径深和洞径密切相关；随着径深的增大，拱顶方向上围岩的结构性参数均呈现出先减小后增大的规律，存在一个最小值。

On the other hand, if the damage position and the damage size are used for description of the structural damage, the mathematical model is actually stated as a discrete structural optimization problem with unknown number of design variables, since the number of damages can not be given in advance.

本文采用极大极小问题构造损伤识别的优化模型，通过凝聚函数将极大极小问题转化为一个目标函数连续可微的无约束优化问题，采用基于灵敏度分析的序列线性规划方法求解。

Based on the ICMmethod,the discrete topological optimization problem about spot-weld's existence or not is transformed into the continuous optimization problem on[0,1].The optimization model is founded with maximizing the structural stiffness as objective and structural strength as constraints.The problem of multi-objectives and multi-constraints is transformed into the problem of single-objective and single-constraint with the K-S function.The displacement and stress are transformed into the explicit function of design variables with the Response Surface Methodology.The optimization model is solved with Sequential Quadratic Program.

基于ICM（Independent Continuous Mapping，即独立、连续、映射）方法，将焊点有无的离散拓扑优化问题转化为[0，1]区间上的连续优化问题；建立了以结构刚度最大为目标、结构强度为约束的连续拓扑优化模型；采用K-S函数将多目标和多约束问题转化为单目标和单约束问题；运用响应面方法将位移和应力转化为设计变量的显式函数，采用序列二次规划方法求解优化模型。

Chimborazo and Cotopaxi, took me by the hand.

越过琴博腊索山和科托帕克西山。

This car is in a good condition.

这辆车的状况很好。