scholarly journals Simulation of the Vibratory Behavior of Slender Shafts Subject to Transverse Loads Moving in the Axial Direction

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
F. Bucchi ◽  
P. Forte
Keyword(s):  
Mathematical Model ◽  
Manufacturing Industry ◽  
Axial Direction ◽  
Transverse Load ◽  
Design Phase ◽  
Vibration Level ◽  
Machine Performance ◽  
Transverse Loads ◽  
Spatial Interval ◽  
Influential Parameters

In various machines of the manufacturing industry, and in particular in paper converting machinery, there are shafts operating under conditions similar to that of a slender beam subjected to a transverse load moving in the axial direction. This condition can lead to vibrations and consequent deterioration of the machine performance and of the product quality. The problem has been theoretically studied in the literature since the 1990s. While shaft mass and stiffness are universally considered among the most influential parameters on its vibratory behavior, less obvious and not investigated in the literature is the influence of the spatial interval between two successive loads, an aspect that should be considered in the shaft design phase. In fact, if that is less than the length of the shaft, i.e., if there is more than one transverse load on the shaft at a given time, the vibration level may decrease with respect to the single-load configuration. This work describes the development of a mathematical model of a slender shaft hinged at its ends, representing the rotor of a paper roll perforating unit, with the SW Mathematica. The effect of a load moving axially at a given speed followed by similar loads after given spatial intervals was simulated investigating the influence of speed and load interval on shaft vibrations and resonance. The results showed how reducing the load interval can lead to a reduction of the shaft vibration which is a useful indication on possible design corrective actions.

Vibration Control of a New Bed Stage System for Ambulance Using MR Dampers

2014 ◽  
Author(s):  
Hee-Dong Chae ◽  
Seung-bok Choi ◽  
Jong-Seok Oh
Keyword(s):  
Mathematical Model ◽  
Vibration Control ◽  
Vibration Isolation ◽  
Design Parameters ◽  
Ride Quality ◽  
Vibration Level ◽  
Mr Dampers ◽  
Secondary Damage ◽  
Stage System ◽  
Magneto Rheological

This paper proposes a new bed stage for patients in ambulance vehicle in order to improve ride quality in term of vibration control. The vibration of patient compartment in ambulance can cause a secondary damage to a patient and a difficulty for a doctor to perform emergency care. The bed stage is to solve vertical, rolling, and pitching vibration in patient compartment of ambulance. Four MR (magneto-rheological) dampers are equipped for vibration isolation of the stage. Firstly, a mathematical model of stage is derived followed by the measurement of vibration level of patient compartment of real ambulance vehicle. Then, the design parameters of bed stage is undertaken via computer simulation. Skyhook, PID and LQR controllers are used for vibration control and their control performances are compared.

The Torsionless Bending of a Hollow Beam by a Transverse Load

1937 ◽  
Vol 4 (1) ◽  
pp. A25-A30
Author(s):  
W. L. Schwalbe
Keyword(s):  
Cross Sections ◽  
Equilateral Triangle ◽  
Bending Moment ◽  
Longitudinal Section ◽  
Transverse Load ◽  
Shearing Stress ◽  
Numerical Work ◽  
Hollow Beam ◽  
Transverse Loads ◽  
Hollow Beams

Abstract The author discusses the bending of hollow beams when subjected to transverse loads, and points out that shearing stresses and strains in the cross sections are necessary, and a particular longitudinal section remains plane only if the resultant of the shearing stress, and hence the plane of the applied bending moment, possesses a particular location. The author determines the location of this resultant shearing stress by applying a method based on St. Venant’s theory. Applications of the method are made to two hollow sections. One of the sections is that of an equilateral triangle which serves as a measure of accuracy for the numerical work presented by the author, since the location of the resultant of the shearing stresses is known by symmetry.

An Approach for the Evaluation of a Product's Process Planning during the Design Phase through a Group Multi-Criteria Decision-Making

2018 ◽  
Vol 38 ◽  
pp. 154-162
Author(s):  
Fatimazahra Guini ◽  
Abdellah El Barkany ◽  
Abdelouahhab Jabri ◽  
El Hassan Irhirane
Keyword(s):  
Process Planning ◽  
Manufacturing Industry ◽  
Major Element ◽  
Hybrid Approach ◽  
Design Phase ◽  
Quality Cost ◽  
Promethee Method ◽  
Industrial Performance ◽  
Manufacturing Time

The process planning of a product represents in the manufacturing industry a major element that determines the level of economic performance of the company. The development and evaluation of process planning during the industrialization phase of a product can cause problems of quality, cost or manufacturing time. Therefore, process planning needs to be evaluated early, during the design phase. The aim of this article is to propose to a manufacturing company a hybrid approach of multicriterion decision support, allowing evaluating the concepts proposed by the designer to choose the best concept having the best industrial performance indicators, and to take into account the opinions of experts from different departments of the company. The multicriterion choice is made by the hybridization of the ROC method and the PROMETHEE method, and the decision criteria are indicators that express the performance of a process planning. Then, to illustrate the capacity of the model, a case study of a product is presented.

Response of a Viscoelastic Annulus to a Step Transverse Load

1970 ◽  
Vol 92 (3) ◽  
pp. 425-434
Author(s):  
S. R. Robertson
Keyword(s):  
Plane Strain ◽  
Poisson’S Ratio ◽  
Logarithmic Decrement ◽  
Poisson's Ratio ◽  
Transverse Load ◽  
Transverse Loads ◽  
Work Done

The problem of finding the response of a viscoelastic annulus in plane strain to step, transverse loads is solved. It is solved by employing Valanis’ method which assumes constant Poisson’s ratio. The resulting displacements are used to calculate the work done by the applied transverse load for various thicknesses of the annuli. A simple spring-dashpot model is then fitted to the work versus time curves so as to provide the logarithmic decrement for design.

Machining Profiling of the Working Rolls as a Way to Control Cross-Section of the Rolled Steel

2013 ◽  
Vol 762 ◽  
pp. 337-342 ◽  
Author(s):  
Aleksandr A. Astakhov ◽  
Dmitriy N. Dunaev ◽  
Igor Mazur
Keyword(s):  
Mathematical Model ◽  
Cross Section ◽  
Axial Direction ◽  
Correct Choice ◽  
Continuous Variable ◽  
Rolled Steel ◽  
Flatness Control ◽  
Deformed State ◽  
Contact Strip ◽  
Control And Management

ncrease of requirements to quality of the flat-rolled steel causes the appearance of new methods and improvement of the well-known approaches to improving the geometry of thin-gage rolled steels. On modern rolling mills, control and management of the strips cross-section is carried out by a profile and flatness control system (PFC). The main channel of the influence of such systems on the geometric parameters of the rolled steel is the axial shifting of S-shaped working rolls in CVC (Continuous Variable Crown) mills. The performance of the PFC is determined by the correct choice of the initial (machining) profile of the working rolls. The paper discusses the way to improve the methodology of grinding S-shaped working rolls by taking into account the stresses, arising in the zone of contact strip with rolls, the elastic deformation of roll system, thermal deformations, arising from the contact with the hot strip and wear of the working layer of the rolls during the campaign. The developed mathematical model of stress-deformed state allows you to determine the places with the highest stresses in the zone of contact strip with working rolls and adjust the initial profile of the rolls to ensure uniformity of extracts of a strip in width with regard to shifting rolls in the axial direction. The mathematical model of the thermal condition of S-shaped rolls, which allows to predict the change of the rolls thermal profile, gives the possibility to create the algorithm for the grinding of the working rolls in hot condition and increase the accuracy of performance of their machining profile.

Effect of Thread and Bearing Friction Coefficients on the Vibration-Induced Loosening of Threaded Fasteners

2007 ◽  
Vol 129 (4) ◽  
pp. 484-494 ◽  
Author(s):  
Basil A. Housari ◽  
Sayed A. Nassar
Keyword(s):  
Mathematical Model ◽  
The Self ◽  
Time Data ◽  
Friction Coefficients ◽  
Rotational Angle ◽  
Transverse Loads ◽  
Threaded Fasteners ◽  
Solid Film ◽  
Loosening Rate ◽  
Bearing Friction

This study provides a theoretical and experimental investigation of the effect of the thread and bearing friction coefficients on the self-loosening of threaded fasteners that are subjected to cyclic transverse loads. The friction coefficients are varied by using different types of coating and lubrication. A phosphate and oil coating and an olefin and molydisulfide solid film lubricant are used on the bolts tested. A mathematical model is developed to evaluate the self-loosening behavior in threaded fasteners when subjected to cyclic transverse loads. An experimental procedure and test setup are proposed in order to collect real-time data on the loosening rate (rate of clamp load loss per cycle) as well as the rotational angle of the bolt head during its gradual loosening. The experimental values of the friction coefficients are used in the mathematical model to monitor their effect on the theoretical results for the loosening rate. Experimentally, the friction coefficients are modified by changing the coating or the lubrication applied to the fasteners. The theoretical and experimental results are presented and discussed.

scholarly journals Mathematical model of the impact assessment of roughness and waviness deviations of races surfaces of rolling bearings on the level of generated vibration

Mechanik ◽  
2019 ◽  
Vol 92 (1) ◽  
pp. 35-37
Author(s):  
Paweł Zmarzły
Keyword(s):  
Mathematical Model ◽  
Mathematical Models ◽  
Impact Assessment ◽  
Ball Bearings ◽  
Vibration Level ◽  
Rolling Bearings ◽  
Shape Deviations ◽  
Specific Frequency ◽  
The Impact ◽  
Dominant Influence

The article presents mathematical models allowing to describe the level of vibration generated by ball bearings 6304-2z type depending on the value of roughness and waviness deviations of inner and outer bearings races. This models will allow to estimate what type of shape deviations have dominant influence on the vibration level generated in specific frequency ranges.

Visualization of Motion Envelope of Parts and Assemblies Based on Simulation or Measurement Data

2006 ◽  
Author(s):  
Johan Lo¨o¨f ◽  
Lars Lindkvist ◽  
Rikard So¨derberg
Keyword(s):  
Manufacturing Industry ◽  
Measurement Data ◽  
Tolerance Analysis ◽  
Suggested Method ◽  
Design Phase ◽  
Simulation Data ◽  
Suggested Algorithm ◽  
Early Phases

As the demand on productivity in the manufacturing industry increases, it's important with tools that shorten the time from concept to production. Visualization has become a popular tool for fast and easy verification regarding many aspects of products in the design phase. In this paper an algorithm is developed to calculate and visualize the total volume in space a part or assembly creates when it is affected by displacement or motion. The algorithm is general and works on all kinds of problem where there is variation or motion involved. The data used to create the total volume is either collected from simulation data or from real measurement data. This paper includes an introduction and background to the problem and a deep explanation of the suggested algorithm. Finally the algorithm is used to visualize the motion envelope of a car engine based on real measurement data. The data and engine is collected from a well known car manufacturer. The result shows that the suggested method for visualization is useful in early phases for design, packaging and tolerance analysis.

An Analytical Model Predicting Fixed Index Assembly Machine Performance

1972 ◽  
Vol 94 (2) ◽  
pp. 419-424
Author(s):  
W. B. Heginbotham ◽  
G. E. Rippon
Keyword(s):  
Mathematical Model ◽  
Analytical Model ◽  
Digital Computer ◽  
Matrix Operator ◽  
Operator Technique ◽  
Machine Performance ◽  
Simplified Method ◽  
The Matrix ◽  
Operating Methods

A simplified method of analyzing the performance of fixed index assembly machines using the matrix operator technique is described. This method can be used widely for exploring the effects of operating methods for assembly machines, and an example is quoted where each workhead has a different reliability. By using a digital computer, an exact mathematical model can be built which will enable studies to be made about machine performance when all the head parameters and method of operation are different for each individual head.

scholarly journals Modifikasi Mesin Pencacah Plastik PET Tipe Gunting dengan Kapasitas 50 kg/jam

2021 ◽  
Vol 1 (2) ◽  
pp. 72
Author(s):  
Nuha Desi Anggraeni ◽  
Alfan Ekajati Latief ◽  
Alvin Rhamdani ◽  
Robby Rinaldi Sandi
Keyword(s):  
Performance Analysis ◽  
Key Words ◽  
Noise Level ◽  
Engine Performance ◽  
Waste Recycling ◽  
Vibration Level ◽  
Machine Vibration ◽  
Engine Efficiency ◽  
Machine Performance

Abstrak Mesin pencacah plastik merupakan sebuah mesin yang dirancang untuk mencacah sampah plastik agar mengurangi volume sampah. Mesin pencacah dirancang mampu mencacah sampah dengan kapasitas pencacahan 50 kg/jam, hasil analisa kinerja mesin pencacah memperlihatkan bahwa kapasitas mesin pencacah adalah 36.68 kg. Analisis kinerja mesin lain adalah: efisiensi mesin nilainya 73,37 %; tingkat kebisingan mencapai 80,6 dB; getaran yang dihasilkan saat melakukan pencacahan adalah 4,9 mm/s2, dan rendemen cacahan 73,45 %. Hasil analisa kinerja memperlihatkan bawah mesin pencacah perlu dimodifikasi agar sesuai dengan hasil perancangan awal. Modifikasi dilakukan dengan mengubah saringan, mengatur ulang jarak antara mata pisau, dan menambahkan pisau pada pisau putar. Modifikasi yang dilakukan berhasil meningkatkan kapasitas mesin pencacah menjadi 42,59 kg/jam; tingkat kebisingan menjadi 76,8 dB; tingkat getaran mesin 3,84 mm/s2; dan kualitas hasil cacahan menjadi baik yaitu plastik terpotong. Kata kunci: modifikasi, kinerja, sampah, daur ulang, mata pisau Abstract The plastic chopping machine is a machine designed to chop plastic waste in order to reduce the volume of waste. The chopping machine is designed to be able to chop waste with a chopping capacity of 50 kg / hour, the results of the chopping machine performance analysis show that the chopping machine capacity is 36.68 kg. Other engine performance analyzes are: the engine efficiency is 73.37%; noise level reaches 80.6 dB; The vibration generated during the counting was 4.9 mm / s2, and the chopping yield was 73.45%. The results of the performance analysis show that the chopping machine needs to be modified to match the results of the initial design. Modifications were made by changing the filter, resetting the distance between the blades, and adding blades to the rotary knife. The modifications made were successful in increasing the capacity of the chopping machine to 42.59 kg / hour; noise level to 76.8 dB; machine vibration level 3.84 mm / s2; and the quality of the chopped results is good, namely the plastic is cut. Key words: modification, performance, waste, recycling, blade

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