Definition of energy efficient law of mechanical impact in vibratory stress relief of metal parts

Oleksii Sheremet,Mykola Ivchenkov,Olena Ivchenkova,Kateryna Sheremet

doi:10.15587/1729-4061.2019.163697

Oleksii Sheremet, Mykola Ivchenkov + Show 2 more

Open Access

https://doi.org/10.15587/1729-4061.2019.163697

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Abstract

The study is based on the method of vibratory stress relief, which is used to reduce the residual stresses in cast and welded parts, and is an alternative to thermal deformation methods, because it is unpretentious to the mass, shape and dimensions of the part. Vibratory stress relief is usually carried out using unbalance electromechanical systems, which are simple in design of the power section and control system. In such systems, processing occurs simultaneously at only one resonant frequency. The workpiece, as a rule, is characterized by several resonant frequencies that have a tendency to shift to the low-frequency region during the implementation of the vibration effect. The technological process of sequential processing at each variable resonant frequency is rather time-consuming and not efficient in terms of the cost of electrical energy. In order to reduce the cost of time and energy, this study proposes the use of the most advanced processing methods at several resonant frequencies. Based on the algorithms of sequential vibratory stress relief at several resonant frequencies of the part and their changes towards low ones, it was proposed to carry out processing by a polyharmonic perturbing force in a limited frequency band. This effect has a bandwidth that contains all the possible frequencies of the part where vibratory stress relief occurs. Such an effect can be realized with the help of an electrodynamic linear motor as an executive body. The advantage of an electrodynamic linear motor is the proportionality of the generated force to the current supplied to the moving conductor and its repetition in form. By means of mathematical modeling for the selected example, it was found that narrowing the frequency range in the low-frequency region by 5 times reduces energy costs by more than 4,000 times as compared with the broadband law of mechanical action on a part. A theoretically determined energy-efficient law can be software-implemented in control systems for electrodynamic linear motors that implement vibratory stress relief

Highlights

Warping of basic parts, as well as distortion of rotational parts, is one of the main reasons for the premature loss of required mutual movement accuracy of various machine components in space
The method of dynamic loading or the method of vibratory stress relief is the impact on the part by means of mecha nical pulses generated according to a certain law [4, 5]
The energy-efficient law of mechanical action during vibratory stress relief of metal parts was determined as a result of the performed research

Summary

Introduction

As well as distortion of rotational parts (shafts, spindles, gears, etc.), is one of the main reasons for the premature loss of required mutual movement accuracy of various machine components in space. The method of dynamic loading or the method of vibratory stress relief is the impact on the part by means of mecha nical pulses generated according to a certain law [4, 5]. It differs from the static load in that the loading and unloading of the part take place cyclically, and the loaded state time is relatively short. Unlike most of residual stress relief methods, vibratory stress relief is undemanding to mass, shape and dimensions of the part It is one of the most versatile ways to reduce residual stresses in cast and welded parts. Energy consumption during vibratory stress relief is an order of magnitude lower than during heat treatment, improving methods of its implementation is an actual scientific and technical problem

Literature review and problem statement

Selection of the executive body for vibratory stress relief

Conclusions