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Tytuł:
FEM simulation of the tube rolling process in Diescher’s mill
Autorzy:
Pater, Z.
Tofil, A.
Powiązania:
https://bibliotekanauki.pl/articles/102656.pdf
Data publikacji:
2014
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
tube rolling
FEM
state of stress and strain
Opis:
This paper deals with the issue of numerical modelling of the piercing process of a thick–walled bush in a two-rolled skew rolling mill, equipped with guiding devices of Diescher’s type. After a short characteristic of the subject matter, the developed geometric model of the process was discussed, with taking kinematics of tools movement and thermal phenomena present in metal during forming into consideration. Next, the results of calculations were presented in a form of fields of strain, damage criterion and temperature. Distributions of force parameters acting on particular tools during the process of bush rolling were also given.
Źródło:
Advances in Science and Technology. Research Journal; 2014, 8, 22; 51-55
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Riveting process simulation - upsetting of the mushroom rivet
Autorzy:
Szymczyk, E.
Jachimowicz, J.
Sławiński, G.
Powiązania:
https://bibliotekanauki.pl/articles/244023.pdf
Data publikacji:
2008
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
riveted joint
mushroom rivet
FEM local model
stress and strain fields
Źródło:
Journal of KONES; 2008, 15, 2; 493-502
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Studies on stress and strain state in cold orbital forging a AlMgSi alloy flange pin
Badania stanu naprężenia i odkształcenia w prasowaniu obwiedniowym sworznia z kołnierzem ze stopu AlMgSi
Autorzy:
Samołyk, G.
Powiązania:
https://bibliotekanauki.pl/articles/353363.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
orbital forging
stress and strain state
aluminium alloy
FEM
experiment
prasowanie obwiedniowe
stan naprężenia i odkształcenia
stop aluminium
eksperyment
Opis:
The orbital forging is one of the metal forming processes which enables the manufacture of products through worm or cold working. A characteristic feature of this technological process is the use of a special wobbling motion of one of the tools in order to reduce the required forming force. This is particularly advantageous during the formation of products in the shape of a disc or a flange pin. Unfortunately, typical constraints of cold orbital forging are: uncontrolled buckling, loss of shape stability (“mushroom effect”) and cracks. They depend on the technological parameters of the process and their cause can be explained on the basis of e.g. workpiece stress state analysis, which is a difficult task due to the complexity of orbital forging process. The article discusses the issues of stress and strain in cold orbital forged parts of the flange pin type, made of AlMgSi aluminum alloy. The results of the presented FEM simulation, verified experimentally, explain the influence of the theoretical aspects of this process on its implementation conditions. It is assumed that orbital forging is performed on the PXW-100A press and the numerical model takes into account all possible variants of the process. Debate boils down to discussing the stress and strain state (e.g. analyzing the stress and strain rate fields) occurring in the workpiece in the context of chosen technological parameters and constrains of orbital forging process.
Prasowanie obwiedniowe jest jedną z technologii obróbki plastycznej, która umożliwia wytwarzanie wyrobów poprzez ich kształtowanie na zimno lub ciepło. Wyroby prasowane obwiedniowo charakteryzują się stosunkowo dużą jakością powierzchni oraz małą tolerancją wymiarową Charakterystyczną oechą tego procesu technologicznego jest zastosowanie specjalnego ruchu wahającego jednego z narzędzi w celu obniżenia wymaganej siły kształtowania. Szczególnie korzystne jest to podczas kształtowania wyrobów typu tarcza lub sworzeń z kołnierzem Typowymi ograniczeniami prasowania obwiedniowego są nie- kontrolowane wyboczenie. utrata stateczności kształtu oraz pęknięcia. Zależą one od parametrów technologicznych procesu, a ich przyczynę można wyjaśnić na podstawie np. analizy stanu naprężenia panującego w wyprasoe. Z uwagi na złożony charakter prasowania obwiedniowego jest to zadanie trudne. W artykule omówiono zagadnienia stanu naprężenia i odkształcenia w prasowaniu obwiedniowym części typu sworzeń z kołnierzem, która jest wykonana ze stopu aluminium AlMgSi. Przedstawione wyniki symulacji, zweryfikowanej doświadczalnie, wyjaśniają znaczenie aspektów teoretycznych tego procesu na jego warunki realizacji Zakłada się. że prasowanie obwiedniowe jest realizowane na prasie PXW-I00A, a model numeryczny uwzględnia wszystkie możliwe warianty realizacji procesu na tej maszynie. Dyskusja sprowadza się do omówienie stanu naprężenia i odkształcenia (analizując prędkość odkształcenia) panującego w wyprasce w kontekście wybranych parametrów technologicznych i ograniczeń procesu prasowania obwiedniowego.
Źródło:
Archives of Metallurgy and Materials; 2013, 58, 4; 1183-1189
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanical response at peri-implant mandibular bone for variation of pore characteristics of implants: A Finite Element Study
Autorzy:
Sarkar, Sulagna
Sahu, Tikeshwar Prasad
Datta, Arijit
Chandra, Nimesh
Chakraborty, Arindam
Datta, Pallab
Majumder, Santanu
Chowdhury, Amit Roy
Powiązania:
https://bibliotekanauki.pl/articles/307131.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
implant stomatologiczny
uszczelnianie
FEM
porous dental implant
pore size
percentage porosity
bone-implant interface
finite element analysis
stress and strain
Opis:
In this paper, the mechanical response of generic dental implants having calculated porosities with varying pore-sizes has been evaluated. The purpose of this study was to compare the developed stress-strain of designed porous implants (i.e., stress at the implant and strain at the peri-implant bone) with that of the non-porous implant. Methods: 3D model of a mandible was prepared from CT scan data and nine generic dental implant models have been designed having 10%, 20%, and 30% porosity with 500, 700, and 900 micron pore size along with a non-porous model for carrying out FE analyses. First, failure analyses of implants, under a biting force of 250 N have been performed. Next, the remaining implants have been further evaluated under average compressive chewing load of 100 N, for mechanical responses at bone-implant interface. Results: Von Mises strain at the peri-implant mandibular bone increases with the increase in percentage porosity of the implant material and maximum implant stress remained much below the yield stress level. Conclusion: Implant stiffness and compressive strength vary as a function of porosity and pore size. Strain obtained on the peri-implant bone is sufficient enough to facilitate better bone growth with the 700 micron pore size and 30% porosity, thus reducing the effect of stress shielding.
Źródło:
Acta of Bioengineering and Biomechanics; 2019, 21, 2; 83-93
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modele globalne i lokalne MES w analizie struktur lotniczych na przykładzie fragmentu skrzydła samolotu PZL M28 Skytruck
Global and local FE models for aircraft structures analyses based on example of the PLZ M28 Skytruck airplanes wing part
Autorzy:
Jachimowicz, J.
Szymczyk, E.
Sławiński, G.
Derewońko, A.
Wronicz, W.
Powiązania:
https://bibliotekanauki.pl/articles/208840.pdf
Data publikacji:
2010
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
struktury lotnicze
połączenie nitowe
proces zakuwania
modele MES
pola naprężeń resztkowych
riveted joint
mushroom rivet
FEM local models
stress and strain fields
Opis:
W niniejszym artykule na wstępie przedstawiono globalne analizy statyczne MES struktury fragmentu skrzydła samolotu PZL M28 Skytruck. W dalszej części pracy zamieszczono kolejno modele lokalne o różnym stopniu szczegółowości, umożliwiające analizy MES obszarów konstrukcji skrzydła z uwzględnieniem połączeń nitowych, analizy poszczególnych szwów nitowych, a w końcu analizy pojedynczych nitów. Omawiane modele lokalne poza warunkami brzegowymi wynikającymi z modeli globalnych i obciążeniami ogólnymi samolotu uwzględniają wybrane czynniki materiałowe i technologiczne oraz ich wpływ na stan przemieszczeń i naprężeń wokół nitu. Na końcu artykułu przedstawiono symulację procesu nitowania nitu grzybkowego w wyniku której uzyskano rozkład naprężeń resztkowych wokół nitu.W analizach wykorzystano systemy MSC Nastran, Marc i Ansys, a zakres analiz obejmował materiały sprężysto-plastyczne oraz sformułowania dużych przemieszczeń i odkształceń, a także wielopłaszczyznowy kontakt powierzchniowy.
The paper deals with the analysis of residual stress and strain fields in a riveted joint. This stage of study concerns improving the fatigue performance of riveted joints in an airframe. Riveting, particularly in aviation, is a traditional but still commonly used method of joining sheet metal components. Aircraft structures are thin-walled ones, with coverings made of thin sheets stiffened by stringers, frames or ribs. Sheets are typically assembled by multiple rivet or bolt joints. Rivets and bolts are also used to joint sheets and stiffeners. Therefore fatigue resistance of the aircraft structure depends on tens of thousands or even hundreds of thousands rivet joints, which are used to build it. Global and local numerical models of the joint are considered with regard to the aim introduced in the paper. Numerical FE simulations of upsetting process are carried out using the NASTRAN and MARC code. Three-dimensional numerical models are used to determine the resulting stress and strain fields at the mushroom rivet and around the hole. This type of a problem requires the use of contact between the elements assembled and non-linear geometric and elasto-plastic multilinear material models to simulate behaviour of the rivet and sheets. The influence of the squeezing force on strain and stress states is studied. A certain solution to the problem connected with non-uniform stress distribution in the rivet hole is proposed and analysed.
Źródło:
Biuletyn Wojskowej Akademii Technicznej; 2010, 59, 1; 35-59
1234-5865
Pojawia się w:
Biuletyn Wojskowej Akademii Technicznej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of stress-strain state of vehicles’ metal structures elements
Autorzy:
Hrevtsev, O.
Selivanova, N.
Popovych, P.
Poberezhny, L.
Rudyak, Yu.
Shevchuk, O.
Poberezhna, L.
Ivanova, A.
Skyba, O.
Shashkevych, O.
Hrytsanchuk, A.
Powiązania:
https://bibliotekanauki.pl/articles/2201126.pdf
Data publikacji:
2022
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
thermomechanical stress
disk brakes durability
stress and strain state
vehicle reliability
braking distance
naprężenia termomechaniczne
trwałość hamulców tarczowych
stan naprężenia i odkształcenia
niezawodność pojazdu
droga hamowania
Opis:
Purpose: Develop a method for determining and evaluating the stress-strain state, in particular the distribution of thermomechanical stresses in the materials of individual rotating parts of vehicles. Design/methodology/approach: The proposed method is based on the principle of gradual approximations of the solution when the boundary conditions are satisfied on the curvilinear limiting surfaces of the disk body. Findings: The proposed method of determining and estimating the distribution of thermomechanical stresses in the disk material makes it possible to take into account the variable geometry: thickness and presence of a hole in the central part of the disk, also correctly determine stress strain state at any point of unevenly heated rotating axial body. Research limitations/implications: The work uses generally accepted assumptions and limitations for thermomechanical calculations. Originality/value: It is proved that in real disks the stress-strain state is spatial, and the well-known method based on the hypotheses of the plane-stress state does not provide the possibility of calculating the values of stresses in the thickness of the disk. The obtained results can be used as a basis for improving the methodology of auto technical examination of road accidents. In addition, they can be taken into account by design engineers of car brake systems.
Źródło:
Archives of Materials Science and Engineering; 2022, 113, 2; 77--85
1897-2764
Pojawia się w:
Archives of Materials Science and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling of stresses and strains in two-layer combined materials at their formation
Autorzy:
Koloskova, G. M.
Powiązania:
https://bibliotekanauki.pl/articles/379456.pdf
Data publikacji:
2019
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
computational material science and mechanics
multi-layer combined material
stress and strain modelling
calendering method
komputerowa nauka o materiałach
wielowarstwowy materiał łączony
modelowanie naprężeń i odkształceń
Opis:
Purpose: The aim of the represented study was to model the behaviour of two-layer combined material during its manufacturing. Design/methodology/approach: The model of material layers joining by means of calender method is built in LS-DYNA software on the basis of finite element method. Using the developed model the study of stress and strain condition changes is carried out. Numerical modelling was carried out for two types of two-layer combined materials in similar conditions. First combination was of high-density polyethylene top layer and aluminium foil bottom layer. Second combination was of high-density polyethylene top layer and low- density polyethylene bottom layer. Joining materials had equal thicknesses. Findings: During formation of two-layer combined materials the primary strain always occurs at the bottom plate of the bottom layer. However, the maximum plastic strain will be represented for the layer with lower elastic modulus value. At the point of the highest loading applied to the two-layer combined material the elasticity condition is changed to the plasticity one and the yield process is registered. Practical implications: Multi-layer combined materials are some of the most advanced types of materials. The quality of the joining of the layers, the strains and the stresses arising in their manufacturing process are the main causes of low interlayer strength. It leads to easy exfoliation and destruction of the material. The results of the study may be used to improve the quality of multi-layer combined materials. Originality/value: For the first time the model was developed for the determination of strains and stresses arising during the formation of multi-layer combined materials by means of calendering method. The calculations of the stresses and strains distribution dynamics for two-layer combined materials are represented for polymer-metal and polymer-polymer layers combinations. The results of the study may be of interest to specialists in the field of multi-layer combined materials designing and manufacturing.
Źródło:
Archives of Materials Science and Engineering; 2019, 97, 1/2; 12-19
1897-2764
Pojawia się w:
Archives of Materials Science and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermoelastic strain and stress fields due to a spherical inclusion in an elastic half-space
Autorzy:
Singh, K.
Muwal, R.
Powiązania:
https://bibliotekanauki.pl/articles/281796.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
uncoupled thermoelasticity
strain and stress fields
potential functions
spherical inclusion
Opis:
In this paper, closed form analytical expressions for thermoelastic strain and stress components due to a spherical inclusion in an elastic half-space are obtained. These expressions are derived in the context of steady-state uncoupled thermoelasticity using thermoelastic displacement potential functions. The thermal strain and stress fields are generated due to differences in the coefficients of linear thermal expansion between a subregion and the surrounding material. The strain and stress components for exterior points of the spherical inclusion are same as those of the center of dilatation. Variations of strain and stress components for exterior and interior points of the spherical inclusion are shown graphically.
Źródło:
Journal of Theoretical and Applied Mechanics; 2017, 55, 4; 1369-1380
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geokinematics of Central Europe: new insights from CERGOP-2/Environment Project
Autorzy:
Caporali, A.
Becker, M.
Fejes, I.
Gerhatova, L.
Ghitau, D.
Grenerczy, G.
Hefty, J.
Medac, D.
Milev, G.
Mojzes, M.
Mulic, M.
Powiązania:
https://bibliotekanauki.pl/articles/224596.pdf
Data publikacji:
2007
Wydawca:
Politechnika Warszawska. Wydział Geodezji i Kartografii
Tematy:
GPS
geodezja
geodynamika w Europie Centralnej
tektonika w Europie Centralnej
naprężenia i odształcenia w Europie Środkowej
GPS Geodesy
Central European Geodynamics
Central European Tectonics
Stress and Strain in Central Europe
Opis:
The CERGOP2 project funded by the European Union from 2003 to 2006 under the 5th Framework Programme benefits from repeated measurements of the coordinates of epoch and permanent GPS stations forming the CEGRN network in Central Europe, starting 1994. We report on the results of the systematic processing of the available data up to 2005. The analysis work has yielded the velocities of some 60 sites, covering a variety of Central European tectonic provinces, from the Adria indenter to the Tauern window, the Pannonian basin, the Vrancea Seismic Zone and the Carpathian Mountains. The estimated velocities define kinematical patterns which outline, with varying spatial resolution depending on the station density and history, the present day tectonic flow in Central Europe.The CEGRN data show that the majority of active contraction originating from the Eurasia Nubia plate boundary and the microplate between them is taken up primarily in the Eastern Alps, the Dinarides, and the Pannonian Basin. After removal from the ITRF2000 velocities of a rigid rotation accounting for the mean motion of stable Europe, the residual velocities have random orientations with 0.3 mm/yr scatter. This Iow figure provides an upper estimate for the level of rigidity of the European Platform. A 2.3 mm/yr north-south oriented convergence rate is implied by our data between Adria and the Southern Alps, and a narrow - -60 km wide- contraction zone in the Southern Alps is identified, consistently with earlier results. An eastward extrusion north of the contraction zone corresponds with the extension of the Tauern Window. In the southeastern boundary of the microplate, 4-4.5 mm/yr motion of Adria decreases to -1 mm/yr through the microplate, its boundary, and the Dinarides mountain range towards the southwestern part of the Pannonian Basin. Our data suggest that if the Pannonian Basin is subject to deformation, then it is most likely to be compressional than extensional. We conclude that compression and associated contraction due to the Adria collision with the Alps and the Dinarides is likely to fade away in the Western and Northern Carpathians, where our velocities and strain rates show no significant deformation.
Źródło:
Reports on Geodesy; 2007, z. 2/83; 7-46
0867-3179
Pojawia się w:
Reports on Geodesy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analytical solution of mixed boundary value problems using the displacement potential approach for the case of plane stress and plane strain conditions
Autorzy:
Deb Nath, S. K.
Powiązania:
https://bibliotekanauki.pl/articles/266247.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
rozwiązanie analityczne
naprężenie płaskie
odkształcenie
wartość graniczna
analytical solution
displacement potential approach
plane stress and plane strain conditions
mixed boundary value problems
Opis:
Two elastic plate problems made of duralumin are solved analytically using the displacement potential approach for the case of plane strain and plane stress conditions. Firstly, a one end fixed plate is considered in which the rest of the edges are stiffened and a uniform load is applied to the opposite end of the fixed end. Secondly, a plate is considered in which all of the edges are stiffened and a uniform tension is applied at its both ends. Solutions to both of the problems are presented for the case of plane stress and plane strain conditions. The effects of plane stress and plane strain conditions on the solutions are explained. In the case of stiffening of the edges of the plate, the shape of the plate does not change abruptly, which is clearly observed in both of the cases. For the plane strain condition, the plates become stiffer in the loading direction as compared to the plane stress condition. For the plane strain condition, there is a significant variation of the normal stress component, σzz at different sections of the plate. The graphical results, clearly identify the critical regions of the plate for the case of the plane stress and plane strain condition.
Źródło:
International Journal of Applied Mechanics and Engineering; 2017, 22, 2; 269-291
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Numerical and Experimental Analysis of Ballizing Process of Steel Tubes
Autorzy:
Dyl, T.
Powiązania:
https://bibliotekanauki.pl/articles/356697.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
numerical analysis
strain and stress state
burnishing (surface plastic forming)
ballizing process
steel tubes
Opis:
This paper presents chosen results of experimental and numerical research of ballizing process of the steel tubes. Ballizing process is a method of burnishing technology of an internal diameter by precisely forcing a ball through a slightly undersized premachined tubes. Ballizing process is a fast, low-cost process for sizing and finishing tubes. It consists of pressing a slightly oversized ball through an unfinished tube to quickly bring the hole to desired size. The ball is typically made from a very hard material such as tungsten carbide or bearing steel. Ballizing process is by cold surface plastic forming of the surface structure, thereby leaving a layer of harder material and reducing its roughness. After theoretical and experimental analysis it was determined that the smaller the diameter of the balls, the bigger intensity of stress and strain and strain rate. The paper presents influence of ballizing process on the strain and stress state and on the surface roughness reduction rate of the steel tubes.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 2A; 807-814
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Influence of Technological Conditions of the Process of Cogging in Flat Dies on the Quality of Two-Phase Titanium Alloys
Autorzy:
Dyja, H.
Tukibay, A. A.
Mashekov, S. A.
Powiązania:
https://bibliotekanauki.pl/articles/354341.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cogging
flat die
stress-strain state
effective stresses and strains
tilting
reduction
Opis:
To create a rational technology of cogging process and to determinate the optimal values of the angles of tilt and single reduction the stress-strain state (SSS) of the blank during cogging in the flat dies was analyzed. By using the finite element method and program MSC.SuperForge quantitative data are obtained and the basic patterns of distribution of SSS, the temperature during the simulation of tilting in flat dies with different angles of tilting and the amount of reduction were established. Sustainable experimental-industrial technology of forging of two-phase titanium alloys was developed and tested.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 2A; 671-676
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Drained Against Undrained Behaviour of Sand
Autorzy:
Sawicki, A.
Świdziński, W.
Powiązania:
https://bibliotekanauki.pl/articles/241226.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
granular soils
stress-strain characteristics
instability line
dilative and contractive behaviour
static liquefaction
Opis:
The incremental constitutive equations describing the pre-failure deformations of sand are presented. These equations were calibrated on the basis of extensive experimental data, obtained from investigations performed in a triaxial apparatus. Incremental equations were calibrated separately for initially contractive and dilative soil samples. Then, they were applied to predict the undrained behaviour of saturated soil samples. In the case of contractive soils, the constitutive equations describe the effective stress paths leading to the static liquefaction. In the case of dilative soils, the effective stress path is different, as the mean effective stress initially decreases, and after passing the instability line, it starts to increase, asymptotically reaching the failure envelope. Theoretical predictions of undrained behaviour are supported by experimental data. The original feature of this paper is that one can predict the undrained behaviour of saturated granular soils on the basis of stress-strain characteristics of the same soil but dry or tested in drained conditions.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2007, 54, 3; 207-222
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biomechanical Loads and Subjective Stress Exposure to Lumber Graders in Sawmill Industry
Autorzy:
Jones, T.
Kumar, S.
Powiązania:
https://bibliotekanauki.pl/articles/90791.pdf
Data publikacji:
2011
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
job analysis
lumber graders
wood product manufacturing
repetitive strain
upper extremity
physical and psychophysical stress
Opis:
The aim of this study was to determine biomechanical loads and subjective stresses on lumber graders and associated morbidity in a high risk and repetitive sawmill occupation. The exposures of all 29 male sawmill worker volunteers were recorded. Motion and posture were studied with electrogoniometers, muscle loads were recorded with surface electromyography, and psychophysical stresses were assessed with subjective responses. Fifty-nine percent of the participants reported greater than moderate discomfort in their taskdominant upper extremity. Job performance required an average range of motion of 44º, 21º, and 52º in flexion/extension, radial/ulnar deviations, and pronation/supination respectively. It also required an average of 9% maximum voluntary contraction force and was repeated an average of 34 times/min. This repetitive exertion over an 8-h shift was deemed to be a significant risk factor associated with prevalent upper extremity morbidity.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2011, 17, 1; 87-97
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Physiological strain in the Hungarian mining industry: The impact of physical and psychological factors
Autorzy:
Varga, József
Nagy, Imre
Szirtes, László
Pórszász, János
Powiązania:
https://bibliotekanauki.pl/articles/2177421.pdf
Data publikacji:
2016-06-30
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
work-related complex stress
physiological strain
health protection and promotion
work pulse
work-related accidents
workplace illumination
Opis:
Objectives The objectives of these investigations completed on workplaces in the Hungarian mining industry were to characterize the physiological strain of workers by means of work pulse and to examine the effects of work-related psychological factors. Material and Methods Continuous heart rate (HR) recording was completed on 71 miners over a total of 794 shifts between 1987 and 1992 in mining plants of the Hungarian mining industry using a 6-channel recorder – Bioport (ZAK, Germany). The work processes were simultaneously documented by video recording along with drawing up the traditional ergonomic workday schedule. All workers passed health evaluation for fitness for work. The effects of different psychological factors (simulated danger, “instrument stress,” presence of managers, and effect of prior involvement in accidents as well as different mining technologies and work place illumination) on the work pulse were evaluated. The statistical analysis was completed using SPSS software (version 13.0, SPSS Inc., USA). Results The work-related physiological strain differed between work places with different mining technologies in groups of 12–18 workers. The work pulse was lowest in bauxite mining (ΔHR = 22±8.9 bpm) and highest in drift drilling in dead rock with electric drilling machine (ΔHR = 30±6.9 bpm). During sham alarm situation the work pulse was significantly higher than during normal activities with the same physical task (ΔHR = 36.7±4.8 bpm vs. 25.8±1.6 bpm, p < 0.001). When work was performed under different psychological stress, the work pulse was consistently higher, while improving the work place illumination decreased the physiological strain appreciably (ΔHR (median, 25–75 percentiles) = 23, 20–26 bmp vs. 28, 25–31.3 bpm, p < 0.001). Conclusions Recording the heart rate during whole-shift work along with the work conditions gives reliable results and helps isolating factors that contribute to increased strain. The results can be used to implement preventive and health promotion measures.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2016, 29, 4; 597-611
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 19

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