Showing papers by "Harbin Engineering University published in 1996"

Scattering of flexural waves and dynamic stress concentrations in Mindlin's thick plates with a cutout

Abstract: Using the complex variable method and conformal mapping, scattering of flexural waves and dynamic stress concentrations in Mindlin's thick plates with a cutout have been studied. The general solution of the stress problem of the thick plate satisfying the boundary conditions on the contour of cutouts is obtained. Applying the orthogonal function expansion technique, the dynamic stress problem can be reduced into the solution of a set of infinite algebraic equations. As examples, numerical results for the dynamic stress concentration factor in Mindlin's plates with a circular, elliptic cutout are graphically presented in sequence.

Petri based analysis method for active database rules

Abstract: A method based on Petri net is presented for analyzing active database rules. Cyclic rule set, inconsistent rule set and contradictory rule set can be detected automatically by using Petri nets. These rule sets can be corrected or rearranged properly by the user in order to guarantee the system's termination, consistency and correctness.

Non-fick's effect study of mass transfer law for transient mass transfer process

Abstract: The physical behavior of the transient mass transfer was analysed. The mass transfer velocity and the non-Fick's effect were presented based on the exprement and heat-mass transfer analogy, the Fick's first law was developed, and the mass transfer differential equation for the transient mass transfer was set up based on it. The exprement was examined by this theory.It is found that this theory discribed accurately the transient mass transfer problem.

Stress-strain field near the crack-tip of an incompress rubber-like material

Abstract: This paper contains an asymptotic finite-deformation analysis about the elastostatic field near the crack-tip in an incompress rubber-like material. The cracktip field is divided into two narrowing sectors and one expanding sector. By the new strain energy function and deformation pattern, we derive and solve the asymptotic equations fo reach sector of the tip field. The singularity of the crack-tip field is discussed. The curves of stress-strain of the crack-tip field for an incompress rubberlike material are given and the dominant behaviors of stress and strain near the crack-tip are revealed.

On the unification of the hamilton principles in nonholonomic system and in holonomic system

Abstract: In this paper by means of typical engineering examples and deep theoretical analysis, we prove that: under the effect of conservative force, the Hamilton principles in holonomic and non-holonomic systems have the same formula δ∫Ldt=0. The formula ∫δLdt=0 is an evolved form of the formula δ∫Ldt=0. Therefore, the two formulas are unified.

Auv fuzzy local path planner design

Abstract: In this paper the method solving AUV local path plan by fuzzy mathematics is presented First, for the moving character of AUV, the translation and rotation rules of AUV is discussed And then sonar informations are disposed by fuzzy mathematics On the basis of summarizing human driving experiences, the AUV local path plan control forms are constituted At last, the avoidance simulation is carried out with computer so the simulative results are given

Application of digital simulation to survivability assessment of a warship power system

Abstract: The paper presents the application of digital simulation to survivability assessments ofwarship power system. The digital simulation models of the damaging probability of elec-tric equipment and the probability of the electric load getting power supply are developed. Based on these models , the digital simulation model of survivability of warship power sys- tern has been deduced, which is a generally applicable means of computer simulation andcan be used to comprehensively assess the survivability of warship power systems. Keywords :digital simulation , warship , power system , survivability,probability1. INTRODUCTION Along with the development of warship automation and the increase of technology content , the running qualities of power system are becoming more and more important to ensure the combat ability and the survival ability of a warship , hence the reliability and thesurvivability of the warship power system are also becoming more important. Further- more , because the warship power system gradually becomes larger and more complicated,the traditional assessing method by the qualitative analysis and the partial physical simula-tion seems hardly to assess the survivability of power system overall and accurately. Espe-cially, it is difficult for the traditionalmethod to offer the probability index of the surviv-ability of major electric equipments and find out the weak link of the power system surviv-ability systematically. Therefore ,

A kind of mixed reasoning in rule-based systems

Abstract: The method of mixed reasoning is put forward in this paper. It can accomplish deductive and abductive reasoning alternatively in a problem-solving process. A problem solving model of the method is defined. The logic reasoning in this model can achieve a change of the reasoning direction. In this paper, some other problems and technologies of completing mixed reasoning are also discussed, such as how the reasoning algorithm is designed and its properties are analysed.

Neural network state space identification model

Abstract: Proposes a novel special neural network state space identification model for system identification (NNSSIM). This novel neural network model is composed of the state equation and the output equation of the system. The neurons and weights in the novel neural network have a clear physical significance. A dynamic backpropagation training algorithm is developed to train NNSSIM. The convergence of the algorithm is analyzed using the Lyapunov stability theorem and the conditions of convergence are given.