International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395-0056
Volume: 09 Issue: 05 | May 2022
p-ISSN: 2395-0072
www.irjet.net
To develop algorithm to create node at desired location on beam using absorber Akshata Waghmare1, Dr. Sushil Patil2 1ME
design Engineering student at SVPM’s College of Engineering Malegaon, Maharashtra, India Mechanical Dept. of SVPM’s College of Engineering Malegaon, Maharashtra, India ---------------------------------------------------------------------***--------------------------------------------------------------------2Associate Professor,
Abstract - The purpose of present investigation is to apply Imposing node method to reduce handle vibration of grass trimmer using variable stiffness vibration absorber. The numerical simulations are conducted to find the effectiveness of proposed method in handle vibration suppression. The laboratory experimental test is carried out to validate the numerical results. The results shows that the vibrations are reduced by 75% at handle support location using proposed method..
absorber frequency to impose node at handle support location of grass trimmer. The numerical and experimental tests are conducted to show the viability of proposed method.
Key Words: Grass trimmer, handle vibration, vibration absorber, imposing node, vibration isolation
1. INTRODUCTION The powered grass trimmers are widely used in the general upkeep of parks and wooded areas in particular for the maintenance of the roadside and also of the railway lines where the outgrowth of the bushes on the railway track must be prevented. The operator of trimmer may subjected to large magnitude of hand arm vibration and may cause complex vascular and neurological and musculoskeletal disorder, collectively named as hand-arm vibration syndrome. Various techniques are used for controlling the vibration at the handle. These includes mounting of a dynamic vibration absorber on the grass trimmer, isolate the hand from the vibrating handle with the use of anti-vibration gloves [1] and isolate the tool handle form the vibrating source by using isolators [2]. The use of vibration isolators, however results in handle with a high mass and low stiffness. The isolation performance of the anti-vibration gloves for different hand tools is influenced by the excitation spectrum or tool type [3]. Alternatively, the excessive vibrations are suppressed by attaching a tunable vibration absorber to the grass trimmer. Hao and Ripin [4] applied imposing node technique to achieve vibration reduction at handle location of the petrol engine grass trimmer using two tunable vibration absorbers. Cha [5-9] discussed the scheme to impose nodes at required locations in a harmonically excited structure using simple oscillators. Patil and Awasare [10] proposed the algorithm to find required neutralizer parameters to create nodes at desired locations on beam.
Fig.1 Grass trimmer system
1.1 Grass Trimmer System A small petrol engine grass trimmer as shown in Figure (1) is considered in the present study. It is powered by an internal combustion engine mounted at one end of hallow circular pipe and rotating cutter head at other end. The nylon string attached to the cutter head cuts the grass. The specifications of the grass trimmer used for numerical and experimental tests are listed in Table 1 .The grass used for study is welldeveloped and dense for which the speed of grass trimmer was around 7000 to 7500 rpm. For laboratory and field test the speed of grass trimmer is selected as 7250 rpm. The hand-transmitted vibration is measured by means of the frequency-weighted root-mean-square (rms) acceleration as per ISO 5349-112. Figure 2(a) and 2(b) shows the axis system for the trimmer pipe and handle respectively. As the single axis accelerometer is available, the sequential measurement (measure in one direction at a time) of vibration is carried using lightweight mounting block which is attached to vibrating surface as depicted in Figure 2(c). The accelerometer is attached to the block for the measurement of x, y and z direction and all the operating conditions remains same for three axis measurements ISO 5349-213.
In the present research imposing node technique is applied to reduce handle vibration of grass trimmer where the engine is mounted on the grass trimmer pipe. The algorithm based on iterative method is developed and applied to find © 2022, IRJET
|
Impact Factor value: 7.529
|
ISO 9001:2008 Certified Journal
|
Page 1530