Summary. A combined bending and twisting theory for a straight beam under external loading is developed in the article. Typical assumptions of beam theory are made for the stresses. For the displacements an assumption is made, in which the conventional rigid body movement of the cross-section is augmented by an axial displacement made up of four warping functions. Simple boundary value problems, which can be solved using the finite element method, are derived for determining the warping functions. The equations of the combined bending and twisting of the beam are derived using the principle of virtual work. The developed theory can be regarded as a generalization of the bending and twisting theory of open thin-walled beams. It, however, applies to all cross-section types even consisting of different materials and takes into account the effect of shear deformation to the deflections of the beam.
{"title":"Taivutuksesta ja väännöstä, Osa I: Teoria","authors":"Jukka Aalto","doi":"10.23998/RM.64856","DOIUrl":"https://doi.org/10.23998/RM.64856","url":null,"abstract":"Summary. A combined bending and twisting theory for a straight beam under external loading is developed in the article. Typical assumptions of beam theory are made for the stresses. For the displacements an assumption is made, in which the conventional rigid body movement of the cross-section is augmented by an axial displacement made up of four warping functions. Simple boundary value problems, which can be solved using the finite element method, are derived for determining the warping functions. The equations of the combined bending and twisting of the beam are derived using the principle of virtual work. The developed theory can be regarded as a generalization of the bending and twisting theory of open thin-walled beams. It, however, applies to all cross-section types even consisting of different materials and takes into account the effect of shear deformation to the deflections of the beam.","PeriodicalId":52331,"journal":{"name":"Rakenteiden Mekaniikka","volume":"50 1","pages":"376-404"},"PeriodicalIF":0.0,"publicationDate":"2017-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49234421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study different fatigue design methods of welded and bolted joints for the agricultural machine based on the strength of materials and standards was applied. The loads that affect the structures of the plough were measured with the strain gauge method. Also the behaviour of the structures during conventional use was analyzed. Based on the measured loads the lifetime of original components made from S355-steel was evaluated. The body of the plough was redesigned using S700-steel and the fatigue design for the components was carried out based on the measured loads. The FE-method was used on stress calculation and components design. The components of the welded joints had to be reshaped to reach the permissible stress level. In the fatigue design, the simplified S-N curve, endurance limit reduction coefficient and stress concentration factors according to strength of materials were used. In the fatigue design of the welded joints, the design was carried out based on the tabulated values of characteristic fatigue strength and structural details. As a result of the study, it was found that the geometry and post-treatment have the greatest impact on the fatigue strength of the welded joint. Furthermore, it was found that the endurance limit of the un-notched material increases when the tensile strength increases. However, the endurance limit of the welded joint does not increase in the same proportion. Also it was found that the total mass of the structure decreases while the fatigue strength increases.
{"title":"Kyntöauran rakenteiden kehittäminen mitatun kuormitusaineiston perusteella","authors":"Lassi Keränen","doi":"10.23998/RM.64418","DOIUrl":"https://doi.org/10.23998/RM.64418","url":null,"abstract":"In this study different fatigue design methods of welded and bolted joints for the agricultural machine based on the strength of materials and standards was applied. The loads that affect the structures of the plough were measured with the strain gauge method. Also the behaviour of the structures during conventional use was analyzed. Based on the measured loads the lifetime of original components made from S355-steel was evaluated. The body of the plough was redesigned using S700-steel and the fatigue design for the components was carried out based on the measured loads. The FE-method was used on stress calculation and components design. The components of the welded joints had to be reshaped to reach the permissible stress level. In the fatigue design, the simplified S-N curve, endurance limit reduction coefficient and stress concentration factors according to strength of materials were used. In the fatigue design of the welded joints, the design was carried out based on the tabulated values of characteristic fatigue strength and structural details. As a result of the study, it was found that the geometry and post-treatment have the greatest impact on the fatigue strength of the welded joint. Furthermore, it was found that the endurance limit of the un-notched material increases when the tensile strength increases. However, the endurance limit of the welded joint does not increase in the same proportion. Also it was found that the total mass of the structure decreases while the fatigue strength increases.","PeriodicalId":52331,"journal":{"name":"Rakenteiden Mekaniikka","volume":"50 1","pages":"405-419"},"PeriodicalIF":0.0,"publicationDate":"2017-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47315811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this article the strain measures in continuum mechanics proposed by Piola and Finger are considered. Their rates and corresponding stress measures are derived. The results are illustrated by two simple examples: bar in tension and simple shear.
{"title":"Venymämitat kontinuumimekaniikassa Fingerin ja Piolan mukaan","authors":"Martti Mikkola","doi":"10.23998/RM.66414","DOIUrl":"https://doi.org/10.23998/RM.66414","url":null,"abstract":"In this article the strain measures in continuum mechanics proposed by Piola and Finger are considered. Their rates and corresponding stress measures are derived. The results are illustrated by two simple examples: bar in tension and simple shear.","PeriodicalId":52331,"journal":{"name":"Rakenteiden Mekaniikka","volume":"50 1","pages":"451-462"},"PeriodicalIF":0.0,"publicationDate":"2017-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48235672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Saivash Danaee, R. Kouhia, P. Rasilo, Anouar Beloahcen, Deepak Singh, M. Ristinmaa
In this paper, a coupled magnetoelastic model for isotropic ferromagnetic materialsis presented. The constitutive equations are written on the basis of the total energy in whichthe right Cauchy-Green strain tensor and the Lagrangian form of the magnetic eld strengthare used as the basic state variables. It is also applied to ferromacnetic electric steel for whichthe material parameters are calibrated.
{"title":"A model for magneto-elastic behaviour","authors":"Saivash Danaee, R. Kouhia, P. Rasilo, Anouar Beloahcen, Deepak Singh, M. Ristinmaa","doi":"10.23998/RM.65307","DOIUrl":"https://doi.org/10.23998/RM.65307","url":null,"abstract":"In this paper, a coupled magnetoelastic model for isotropic ferromagnetic materialsis presented. The constitutive equations are written on the basis of the total energy in whichthe right Cauchy-Green strain tensor and the Lagrangian form of the magnetic eld strengthare used as the basic state variables. It is also applied to ferromacnetic electric steel for whichthe material parameters are calibrated.","PeriodicalId":52331,"journal":{"name":"Rakenteiden Mekaniikka","volume":"50 1","pages":"349-352"},"PeriodicalIF":0.0,"publicationDate":"2017-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42051002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Heilala, T. Kuivaniemi, Juho Könnö, T. Frondelius
The Natural frequency and vibration response calculation process of a generator set was automatized so that it can be used in a generator set common base frame concept design. The implementation of automatization was to be done so that no profound knowledge about the finite element method is needed to execute calculations and that computation times are short. Substructuring is used for certain parts of the generator set model to reduce the computation times for more a efficient concept design process. The common base frame concept design is implemented to the process by using a design tool in which the finite element model generation from parametric geometry is automatized. Generator set finite element model generation, natural frequency and vibration response calculations and post-processing of analysis results were implemented by developing a calculation tool for this purpose. The calculation tool is an independent application that uses Abaqus simulation software to execute analyses.
{"title":"Concept Calculation Tool for Dynamics of Generator Set Common Baseframe","authors":"J. Heilala, T. Kuivaniemi, Juho Könnö, T. Frondelius","doi":"10.23998/RM.64925","DOIUrl":"https://doi.org/10.23998/RM.64925","url":null,"abstract":"The Natural frequency and vibration response calculation process of a generator set was automatized so that it can be used in a generator set common base frame concept design. The implementation of automatization was to be done so that no profound knowledge about the finite element method is needed to execute calculations and that computation times are short. Substructuring is used for certain parts of the generator set model to reduce the computation times for more a efficient concept design process. The common base frame concept design is implemented to the process by using a design tool in which the finite element model generation from parametric geometry is automatized. Generator set finite element model generation, natural frequency and vibration response calculations and post-processing of analysis results were implemented by developing a calculation tool for this purpose. The calculation tool is an independent application that uses Abaqus simulation software to execute analyses.","PeriodicalId":52331,"journal":{"name":"Rakenteiden Mekaniikka","volume":"50 1","pages":"353-356"},"PeriodicalIF":0.0,"publicationDate":"2017-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42847183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jussi Korhonen, J. Kuoppala, Miikka Väntänen, J. Vaara, Mikko Turunen, Panu Kämäräinen, J. Laine, A. Silvonen, T. Frondelius
This article describes the fatigue testing of QT steel in ultrasonic frequencies. Different possibilities, challenges and prejudices are reviewed.
本文介绍了QT钢在超声频率下的疲劳试验。不同的可能性，挑战和偏见进行审查。
{"title":"QT steel High Cycle Fatigue Testing with Ultrasonic","authors":"Jussi Korhonen, J. Kuoppala, Miikka Väntänen, J. Vaara, Mikko Turunen, Panu Kämäräinen, J. Laine, A. Silvonen, T. Frondelius","doi":"10.23998/RM.65059","DOIUrl":"https://doi.org/10.23998/RM.65059","url":null,"abstract":"This article describes the fatigue testing of QT steel in ultrasonic frequencies. Different possibilities, challenges and prejudices are reviewed.","PeriodicalId":52331,"journal":{"name":"Rakenteiden Mekaniikka","volume":"50 1","pages":"304-308"},"PeriodicalIF":0.0,"publicationDate":"2017-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47525916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Deepak Singh, Kati Mökkönen, J. Poutala, P. Rasilo, A. Belahcen, R. Kouhia
In this paper some preliminary results on the eect of plastic deformation onmagnetic properties of an electric steel are presented. Both experimental results and modellingaspects are discussed.
本文介绍了塑性变形对电工钢磁性能影响的一些初步结果。讨论了实验结果和模型方面的问题。
{"title":"Preliminary results on the effect of plastic deformation on magnetic properties","authors":"Deepak Singh, Kati Mökkönen, J. Poutala, P. Rasilo, A. Belahcen, R. Kouhia","doi":"10.23998/RM.65180","DOIUrl":"https://doi.org/10.23998/RM.65180","url":null,"abstract":"In this paper some preliminary results on the eect of plastic deformation onmagnetic properties of an electric steel are presented. Both experimental results and modellingaspects are discussed.","PeriodicalId":52331,"journal":{"name":"Rakenteiden Mekaniikka","volume":"50 1","pages":"372-375"},"PeriodicalIF":0.0,"publicationDate":"2017-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43742981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. Väisänen, A. Mäntylä, Antti Korpela, T. Kuivaniemi, T. Frondelius
This article describes the overview of crankshaft analysis of a medium speed dieselengine. Crankshaft analysis includes static analysis, crankshaft dynamics, bearing analysis, gearanalysis, and stress & fatigue analysis, the latter being in main focus in this article. AVL ExcitePower unit is used for multi-body dynamics and Abaqus for finite element analysis.
{"title":"Medium Speed Engine Crankshaft Analysis","authors":"I. Väisänen, A. Mäntylä, Antti Korpela, T. Kuivaniemi, T. Frondelius","doi":"10.23998/RM.64916","DOIUrl":"https://doi.org/10.23998/RM.64916","url":null,"abstract":"This article describes the overview of crankshaft analysis of a medium speed dieselengine. Crankshaft analysis includes static analysis, crankshaft dynamics, bearing analysis, gearanalysis, and stress & fatigue analysis, the latter being in main focus in this article. AVL ExcitePower unit is used for multi-body dynamics and Abaqus for finite element analysis.","PeriodicalId":52331,"journal":{"name":"Rakenteiden Mekaniikka","volume":"50 1","pages":"341-344"},"PeriodicalIF":0.0,"publicationDate":"2017-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42711493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This article presents experiences of topology optimization. In the example, commercial software is used to find the optimal topology of the cast iron part.
本文介绍了拓扑优化的经验。在实例中，使用商业软件寻找铸铁件的最优拓扑。
{"title":"Topology optimization of cast iron parts","authors":"Timo Turkkila","doi":"10.23998/rm.64936","DOIUrl":"https://doi.org/10.23998/rm.64936","url":null,"abstract":"This article presents experiences of topology optimization. In the example, commercial software is used to find the optimal topology of the cast iron part.","PeriodicalId":52331,"journal":{"name":"Rakenteiden Mekaniikka","volume":"49 9","pages":"368-371"},"PeriodicalIF":0.0,"publicationDate":"2017-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41273816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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