A CONSTITUTIVE FUNCTION FOR A NONLINEAR ANALYSIS OF STRUCTURES OF LINEAR ELEMENTS

In this paper, a constitutive function in form of integration is presented for a nonlinear analysis of structures of linear elements. With applications of a constitutive function, the truss and frame elements material nonlinear stiffness equations are derived. The results shows the convenience in numerical analysis and the ability to solve some difficult problems in tn the structural behavior study both in loading and unloading process by use of the presented constitutive function.     

LARGE DEFLECTION OF A CIRCULAR PLATE ON PASTERNAK FOUNDATION UNDER A CONCENTRATED LOAD AT THE CENTER

Based on Karman's nonlinear foundamental differential equations, the new method combines perturbation method with integral equation method is forward to solve nonlinear bending of a clamped circular plate on Pasternak foundation under a concentrated load at the center. This method is simple and easy to use. The numerical results show that the present solution is reliable.     

NONLINEAR ANALYSIS OF LAMINATED ANGLE-PLY PLATE USING A HIGHER-ORDER SHEAR DEFORMATION THEORY

A higher-order shear deformation theory is used to analyse nonlinear bending of symmetrically laminated angle-ply rectangular plates. The nonlinear governing differential equations are solved here by using perturbation method. Numerical rerults are presented graphically for vairous parameters of laminated plate. The present solutions are compared with those obtained using the classical plate theory. A lot of significient conclusions are obtained.     

A NERUAL NETWORK FOR THE ADAPTIVE CONTROL OF A 2 ORDER NONLINEAR SYSTEM

This paper presents a new method of self tuning adaptive control which adopts a neural network to identify the characteristics of a second order nonlinear system, which is in turn applied to adaptive control. The simulations show that the method has good capability of sduty and adaptation.     

A METHOD OF SYSTEM IDENTIFICATION AND MODEL REDUCTION BASED ON TIME-DOMAIN RESPONSE OF A DYNAMIC SYSTEM

This paper combines model reduction with system identification by means of time-domain function approximation, and presents a new time domain method of direct identification of linear reduced model and model reduction, and demonstrates existence theorem of its solution and criterion of order determination. Simulation tests show that the method is simple, accurate with few data requirement.     

A Kind of Adaptive Generalized Predictive Control for a Nonlinear System

This paper,using Hammerstein model to express a kind of nonlinear system,presents a new kind of Adaptive Generalized Predictive control for Nonlinear systems(NAGPC). This method divides the whole system into two parts: linear subsystem and nonlinear one. In the first part,a new algorithm ,whose computation quantity is less and speed is faster,is developed according to the characteristics of gain controlling Matrix F in the Generalized Predictive Control (GPC). Mean while, the interpolation method is used to develop one step root solving procedure and the result can be used as the whole system input in the second part. Simulation studies show that the general algorithm NAGPC is strong in robustness,good in stability and fast in computation.     

Curvature Force Method for Nonlinear Analysis of Prestressed Concrete Frame

In this paper, based on the structure characters and load applying means, a method called as curvature force method is put forward and proved in the nonlinear analysis of bonded prestressed concrete frame. Based on the nonlinear program, the simulation calculation was carried out on test results of two prestressed concrete frames by this method. The results from calculation are identical with the experiment ones. So it may be added to the methods for the nonlinear analysis of prestressed concrete frame.     

VaR Model and Application to Securities Investment Management

VaR model is one of methods to measure and control market risk.This paper analyzes VaR model principle and its main factors.According to function relation,the relationship between the portfolio value and its market risk factors are sorted in two kinds: linear and nonlinear.The method of calculating the VaR is put forward.Finally,the article analyzes the application of VaR model to portfolio,risk control,information disclosure and financial supervison.     

The Approximate Method of Quadratic Function With Mixed Constraint

A reduced method to solve the problem with equality constraints is given. Based on the reference we use nonlinear equality constraints, the approximate algorithm is obtained. The nonlinear programming of quadratic function with equality and unequality constraints is discussed by Wang kairong. We transform unequality constraints into equality constraints by add to relaxation variable, the quadratic programming is obtained by linear approximation, and approximate calculation is done by means of reduced method. The result of numerical calculation shows the method is feasible.     

The Geometric precision and Performance Analysis for machining Surface based on Fractals

A new analysis method for machining surface profile error is presented in this paper.The linear regression and nonlinear regression are first applied respectively,and then the Weierstrass Mandebrot fractal function is used to obtain the fractal parameters of machining profiles.A minimal parameter set which depicts the machining surface geometric precision is set up,and the surface profile can be reconstructed using these parameters,and an analysis method for part performance and its tolerance structure is proposed.Examples are provided to illustrate the method is feasible and effective.     

ANALYSIS OF THE ZERO SOLUTION STABILITY OF LAMINAR BOUNDARY LAYER EQUATION

Two-dimensional incompressible laminar boundary layer equation can be changed into Blasius equation by means of similarity transformation. In this paper, Blasius equation 2f" '+ff"=0 is transferred into a nonlinear and autonomous system of second order by variable transforming. Taking the advantage of its approximation to linear system, the stability near zero solution can be discussed.     

Equivalent Duffing System Method of Nonlinear System Dynamic Reliability Analysis

Equivalent linear system method is the main method of nonlinear structural system random response analysis. While it would generate big error when the results of equivalent linear system method are used to analyze the structural dynamic reliability. Through minimum mean square error principle, general nonlinear system was converted to equivalent Duffing nonlinear system, based on which the structural dynamic reliability was analyzed. The accurate steady state analytic solution of Duffing nonlinear system can be worked out by FPK equation, so it is not only convenient but also accurate to analyze structural dynamic reliability by using the equivalent nonlinear system method. It is also shown that the analysis results of equivalent nonlinear system method presented here is reliable and the calculation accuracy is higher than equivalent linear system method apparently through the example analysis.     

THE ARC-LENGTH METHOD OF SECANT RIGIDITY IN FRAME ANALYSIS

The secant rigidity is used for the are-length method to solve the nonlinear finite elements problems. The advantage of this method is unnecessary of calculating the initial resistance term caused by the incremental step. The computational work is less and the programing is easier as compared with initial are-length method. This method can be widely used to solve nonlinear problems.     

Algorithm for the Nonliiear Programming with Lineare Equality Constraints

On the base of the algorithm that is gained by TongDongFu in his master degree paper in 1999,the autrors add accurate one dimension search method(Newton method)into it and gained a new algorithm for the nonlinear programmign with linear equality constraints.Some examples are given to testify the availability of this algorithm.     

THE ELESTOPLASTIC DYNAMIC ANALYSIS OF RC PLANAR FRAMES AND ITS PROGRAM

This paper makes use of a beam-colunm model in the elastopl-astic dynamic analysis of RC planar rames.For which an improved method is presented to estabish the envelopes of moment-curvature relationships by appli-cation of RC nonlinear analysis,and a program named PFEPDA suitable to mic-rocomputer is developed.     

A MEW HIGH-SPEED METHOD OF TOOL-LIFE TESTING

This paper inferred a new high-speed method of tool-life testing from the differential median theorem of the pluralistic function. The characteristic of the method is that by using one cutting edge and doing one wear curve the tool life equation T=Cvx can be obtained.The drain on the workpiece and time of the method decreased by 2/3 as compared with that of the conventional testing method. The test has verified the method in the paper.     

RESEACHES OF STRESS CONCBNTRATION PARAMETER ON THE STEEL CRANE BEAM WITN RIGNT ANGLE SUDDEN CHANGE HEIGHT NEAR SUPPORTS

Using the method of homogenous testing design this paper analyses a steel cranebeam with right angle sudden change height near supports of different geomitry parameters by the fi-nite elements.The part of height stress point and the stress con cen tration parameter in the beam arefound.After analysing more element nonlinear regression,the relationship between stress concentra-tion parameter and geomitry parameter is established.This paper also discusses both source ofanalysing result error and effect.     

THE ELIMINATION OF UNDETERMINED MULTIPLIERS OF MOTION EQUATIONS OF NONHOLONOMIC SYSTEMS

This paper studies several kinds of motion equations of nonlinear nonholonomic constraint systems. On the basis of the motion equations of the first order nonholonomic system and the theory of the zero factor of matrix multiplying from the left, the general equations of the system without undetermined multipliers is derived. By applying the method to arbitrary order nonholonomic systems, the motion equations of the systems are gained.     

Fuzzy Adaptive Variable Structure Control of Speed Process of DC Motor

The load changed of motor affects normal run. If it is not adjusted, the state of motor will become poor, while it affects steady of the system. This paper presents an efficient method for the motor speed controlling, it applies Tacagi-Sugeno's method that each linear submodels are connected for fuzzy algorithm, an algorithm of the fuzzy model identifying and fuzzy control is fulfilled through whole nonlinear model which are replaced with local linear models. It makes speed of motor to maintain steady, and variable structure control is applied to guarantee performance of dynamic flowing for process controlled, the design of stability and robustness is proposed in the scheme. Practice running results show that it is efficient that uncertain dynamic processes are controlled.     

THE APPLICATION OF MULTIBODY DISCRETE METHOD IN RING''S VIBRATION ANALYSIS

A ring's muJtibody discrete model is discussed in this paper. The ring's plane geometric nonlinear vibration equations are derived. Compared with the finite element and lump mass methods, this method is better. In the last pa it of the paper, the eigenvalues, the first 9 modes of the ring, the geometric nonlinear dynamic responses of the ring are calculated.