Li Yang Xie

Strength and Reliability Analysis of Hydraulic Support

Hydraulic support is an important equipment of synthesis mechanization caving coal and safe production in modernization coal mine. According to the research object of ZF5000/16/28’s mould hydraulic support, stress distribution of dangerous parts is obtained by stress testing and ANSYS software. The relevant total displacement distribution rule and equivalent stress distribution rule of the type hydraulic support prototype were found. At the same time, reliability analysis of a single stent and stent system reliability prediction were carried out, which guides design and use of hydraulic support in theory better.

Failure Analysis and Reliability Evaluation of a Planetary Gear Box

With the qualities of smooth operation, high efficiency and small size, the planetary gear box was widely used in transmission field. In this paper, a 2-stage planetary gear box was studied. CAXA and Pro/E were used for modeling. The FEA analysis results were obtained by ANSYS, both the contact stress and the bending stress of the gear tooth root. The results showed that with the continuous action of cyclic loads, the excessive contact stress is the direct reason of the failure. Then, the system reliability evaluation was made, which can provide guidance for engineering practice.

Transverse Vibration Analysis of Euler-Bernoulli Beams Carrying Concentrated Masses with Rotatory Inertia at Both Ends

Transverse vibration analysis is presented for Euler-Bernoulli beams carrying concentrated masses and taking into account their rotatory inertia at both ends. The dimensionless eigenfunctions for the problems are first obtained using the differential equations of motion and considering translational and rotatory springs at both ends. A numerical technique, the Newton–Raphson algorithm, is then used to solve vibration eigenfunctions of the beams. Finally, the influences of different non-dimensional parameters on frequencies are discussed.

Residual Strength Degradation Model for Low-Alloy Steel in High Cycle Fatigue Load

Residual strength degradation of 35CrMo alloy steel is investigated experimentally and theoretically in this paper. The experimental results were obtained by high-frequency fatigue testing machine and electro-hydraulic servo testing machine at room temperature. The experimental results showed the true tensile strength under static load and the residual strength under different cycle ratio, respectively. An exponential degradation model was proposed relating the initial strength, residual strength to the applied fatigue cycles and the constant amplitude stress. The residual strength distribution was described using three-parameter Weibull probability density function. The mathematical software MatLab was used for parameter estimation. Finally, the distribution function and failure probability density function of the residual strength was received, which was significant in fatigue reliability.

Finite Element Analysis of a Compressor Disk

Compressor disk is a key rotor part of aeroengines. Alone with the increase of thrust weight ratio of aeroengines, the work conditions of compressor disk are more and more rigor. So the stress level of compressor is very high nowadays. As we know that the stress analysis is a basic of age analysis and reliability analysis, Do a finite element analysis (FEA) is necessary before and after the compressor disks have been made. In this paper, a detail analysis was done with finite element method (FEM), and the stress distribution of disk we got was consistent with the real stress distribution. Also the FEA results show that the location of maximum stress is the failure site of the disk. It is useful work for further work.

The Optimal Maintenance Period for Repairable Product after Warranty Expiration under Renewing Warranty

A model of the optimal maintenance period for repairable product after warranty expiration under renewing warranty is proposed. In the process to fulfilling warranty, the failures of product within warranty period happen randomly, the replacements of products successively failed with warranty period form a renewing process. Given failure rate of product, the period of fulfilling warranty is function of warranty period. User purchasing a product is considered an investment; the period of fulfilling warranty and the maintenance period after warranty make up the life cycle of product investment. Taking various cost factors into account, making model of the cost rate in life cycle of product investment under renewing warranty, the cost rate is function of maintenance period. Give the failure rate of product is an increasing function, it is derived that there is unique optimal maintenance period minimizing the cost rate. Finally, numerical example is given for illustration.

Damage Monitoring and Analysis of Fiber-Metal Laminates with an Open Hole Using Digital Image Correlation

Notched fiber-mental laminates are susceptible to damage. Nowadays, damage detection mainly depends on visual inspection and C scan. But the two methods are limited to the technical skill of the inspectors, causing missed detection or even fault detection. This paper devotes to exploring the DIC monitoring technique to assess of the damage process taking place in notched (open hole) specimens under uniaxial tensile loading. Two-dimensional (2D) Digital Image Correlation (DIC) techniques are employed to obtain full-field surface strain measurements of GLARE3-3/2 and GLARE6-3/2 laminate with an open circular hole under tensile loading. Failure modes,damage initiation and progression of notched fiber-metal laminates are characterized and discussed.

Comparison for the Test Methods of Fatigue Life of Welded Structures

Taking the local parts of high-speed training service as the research object, the static form of the finite element model is established, and the dangerous parts of the stress distribution under different load form corresponding to loading and displacement conditions applied in experimental test is calculated. Fatigue life of the same welding parts of the different forms due to the state of the uniaxial tensile and the bending is respectively tested in the lab, the life distribution and characteristics of their statistics are obtained; Compared to the stress distribution of dangerous parts and data of the test, analysis that the similar parameters of life and failure forms can be received if it choose the reasonable load parameters in different form and loading in the test.

Dynamic Analysis of Slide Vane Compressor Stator Based on Finite Element Method

Mode analysis is important for slide vane compressor stator. Because of period force may set up resonance in the stator. In this paper, the stress distributions and vibration modes of stator of sliding vane compressor were studied through finite element method (FEM). The first-order vibration mode to five-order vibration mode of stator were computed. The results showed that the resonance frequencies are much larger than the working frequency. It is significant for sliding vane compressor design, fatigue life prediction and reliability assessment.

The Body Structural Optimization Based on Safe Side Impact

In view of analyzing the whole side crashworthiness, based on C-NCAP side impact regulations, this study has analyzed the structural characteristics influencing the side impact of car, and proposed the corresponding structural optimization case. According to FEM, the body optimization case has been simulated and contrasted with the real results. As a result, a good side crashworthiness of the car has been obtained, which helps reduce the cost and the quality of the car. Besides, the study has also done simulation work of the rigidity and modal of the body-in-white and compared it with the real results, which has further tested the correctness of optimization model and helped achieve effective approaches to the design of the car side crashworthiness.