| Human comfort which measures the quality of modern high-speed traction elevator is one of the important indicators, in addition to the factors of installation, the choice of design schemes and methods are the determinants of congenital "good" or "bad" of elevator. Therefore, the study of a scientific and rational design theory and method will have great significance for improving the practicality and market competitiveness of products.First, aiming at the limitation of existing axiomatic design theory in obtaining information and application range, a method of fuzzy evaluation for design scheme is proposed based on information axiom. Between target area and evaluation index area, a zigzag mapping model is established based on zigzag mapping process among different areas of axiomatic design, meanwhile an evaluation index system was established for product design scheme. According to the relations between the different evaluation index attribute and design range, the evaluation indexes are divided into different types and membership grade can be described by the normal fuzzy distribution curve and the calculation method is given for the corresponding information of index. The amount of information of every design alternatives is calculated, the best scheme is then determined by comparing the total information content. This evaluation model is used to identify design scheme of high-speed elevator flexible hoisting system, and the results show that the top car driven single-deck elevator has the minimum total information, so it is the best scheme. The method can avoid the influence on the evaluation results of artificial subjective.Second, according to the prefer product design scheme, considering the fuzziness of fault message and the polymorphism of fault state of components and systems, a reliability analysis method of multi-state system is put forward based on fuzzy Bayesian networks. The fuzzy set theory was introduced into the Bayesian network analysis, using fuzzy numbers and fuzzy subsets of nodes to describe the fault states and the fault rates respectively, and the uncertainty of fault logical relationship between nodes were described by fuzzy conditional probability tables, and then fuzzy Bayesian network model was established, meanwhile, taking advantage of the established fuzzy Bayesian networks model to carry out quantitative analysis of multi-state reliability, and finding out the key component affecting system reliability. At last, the method is applied in the reliability analysis of high-speed elevator lift flexible lift system, analyzing the reliability and the degree of importance of every important component. The results show that rope spring failure has the maximum importance to the accident of elevator excessive vibration accident under the condition of known components’failure state. Importance analysis results provide a theoretical basis for subsequent reliability sensitivity analysis.Third, Targeting at realizing analysis of resonance reliability sensitivity for high-speed elevator hoisting systems, the whole lift system and cabin system were respectively taken as the object of study. The dynamical equations for vertical vibration of high-speed elevator hoisting systems and lateral vibration of cabin system were established based on Lagrange equation. Natural frequencies for free vibration of high-speed elevator hoisting systems were analyzed. According to the stability criterion of vibration for mechanical system, considering the uncertainty of parameters, vibrating load and the changing of vibration frequency, the limit state function of resonance failure for hoisting systems was built. The resonance reliability parameters sensitivity of hoisting systems and cabin system during the changing of vibration frequency was researched based on perturbation theory and sensitivity theory. Identifying the more important structure parameters influenced to resonance reliability sensitivity. The results show that the order of the more important structure parameters influenced to resonance reliability sensitivity is top car wheel rotational inertia, the quality of roller, car top wheel mass and moment of inertia of wheel.The analysis results will provide reference for designing, manufacture and maintenance of high-speed elevator hoisting systems.The fourth, in order to achieve the multi-objective problem reliability robust optimization design of the improved system, considering the uncertainty of the external environment, the error of geometric size and loads, distinguishing the design variables and pre-set included in vibration problems, reliability constraints are established on the basis of the random perturbation method of reliability design. Sensitivity additional items of the objective function and constraint function are generated through the sensitivity analysis of the objection function and constraints. Reliability robust optimization design model is constructed which is based on sensitivity additional objective function. The influence degree of design variables of each design goal is determined by using orthogonal test and analysis of variance techniques based on the independence axiom. Design parameters are grouped under the form of no coupling or quasi-coupled design. The multi-objection optimization problem is transformed into the single objective problem. Repeated weigh among several design objectives is then avoided. Reliability robust design of vertical vibration of high-speed traction elevators flexible lifting system is achieved by combining augmented multiplier method and using MATLAB Optimization Toolbox. By numerical example of TBJ 1600/5.0 type elevator, car harmonic response under the single excitation decreased from 93.9549mm/s2 to 44.2048mm/s2 and the design improved the dynamic comfort of high-speed elevators. Kinetic parameters robust design problem of vertical vibration elevator system is solved validly.Finally, dynamic performance test bench of flexible lifting system is constructed with the help of Ben-speed Elevator Co., Ltd. Shandong Experimental tower based on the theoretical analysis. According to the actual characteristics of vertical vibration elevator car, the influence of the change of stiffness of the base rubber tractor, rubber between the car and the car frame, spring stiffness of rope, rubber stiffness of heavy wheels, car roof round rubber stiffness on natural frequencies of lifting system and dynamic response of the car is studied. According to the measuring of experimental test platform, the A95 reduced 9.4mg, the maximum peak value reduced 8.2 mg, the reliability increased from 0.9463 to 0.9998. The car system’s reliability and robustness have been improved. According to the actual experimental results, the feasibility and reliability of the theoretical model is verified. |
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