Plastic deformations of steel frame: statics and dynamics
When all deformations of a column are elastic, transverse deflections of the column depend on transverse force and axial displacements depend on axial force only. These classical dependences are unsuitable for elastic-plastic deformations. Plastic deformations develop in columns when steel frame is...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Vilnius Gediminas Technical University
2010-09-01
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| Series: | Engineering Structures and Technologies |
| Subjects: | |
| Online Access: | https://www.bme.vgtu.lt/index.php/EST/article/view/7519 |
| _version_ | 1818380322242297856 |
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| author | Vytautas Kargaudas Nerijus Adamukaitis |
| author_facet | Vytautas Kargaudas Nerijus Adamukaitis |
| author_sort | Vytautas Kargaudas |
| collection | DOAJ |
| description | When all deformations of a column are elastic, transverse deflections of the column depend on transverse force and axial displacements depend on axial force only. These classical dependences are unsuitable for elastic-plastic deformations. Plastic deformations develop in columns when steel frame is influenced by extreme action. When a steel column is in the elastic-plastic state, the distribution of elastic and plastic deformations in the cross-section depends on both the bending moment and compressing force. The ideal elastic-plastic material is assumed in this investigation (Prandtl stress – strain diagram). If the shape of the column section is double tee, flange width is neglected with respect to web height, but the area of the flange cross-section is assumed a constant. Single-sided or double-sided yield depends on the moment and force, and therefore curvature and the axial strain of the column can be calculated when yielding dependences are determined. Transverse and axial displacements of the highest point of the column are deduced by integration and depend on two arguments: bending force and axial force. These dependences are essentially non-linear, so linear approximations can be assessed for some vicinity of axial force and bending moment values. When axial force is a constant and transverse force increases, both axial and transverse displacements tend to increase. If transverse force is a constant and axial force increases, both displacements increases but dependence lines remain different and depend on cross-section shape parameter equal to the ratio of the flange area and the area of the whole cross-section. A distinguished feature of plastic deformations is dependence on the history of loading a frame of which can be selected in an arbitrary way by an investigator if a quasi-static solution is under examination. The loading of a frame and inertia forces have to be deduced if dynamic analysis is studied. Not only the ultimate result but also the way of approaching a plastic piston – plastic hinge is important. The bended and compressed column is the structure when inelastic dynamic analysis is really important.
Plieninio rėmo plastinės deformacijos: statika ir dinamika
Santrauka
Plastinės deformacijos atsiranda, kai plieninį rėmą veikia ekstremalios apkrovos. Jei plieninėje kolonoje yra tampriosios ir plastinės deformacijos, tai įtempių išsidėstymas skerspjūvyje priklauso nuo lenkimo momento ir gniuždymo jėgos. Vienpusis arba dvipusis takumas priklauso nuo momento ir ašinės jėgos, todėl kolonos kreivis ir ašinė santykinė deformacija gali būti apskaičiuoti, kai takumo priklausomybės nustatytos. Aukščiausio kolonos taško ašinis ir skersinis poslinkiai apskaičiuojami integruojant ir priklauso nuo dviejų argumentų: lenkimo jėgos ir gniuždymo jėgos. Svarbi savybė, susijusi su plastinėmis deformacijomis, yra jų priklausomybė nuo apkrovimo istorijos, t. y. nuo apkrovimo eigos. Jei tiriamoji problema yra kvazistatinė, tai apkrovimo eiga gali būti paties tyrėjo laisvai parenkama. Jei tiriama plieninio rėmo dinamika, tai rėmo apkrova, inercijos jėgos turi būti atrasti. Ne tik ribinė reikšmė, bet ir artėjimo kelias prie plastinio stūmoklio – plastinio lanksto – turi būti atrastas ir yra svarbus. Lenkiama ir gniuždoma kolona yra viena iš konstrukcijų, kuriai dinaminė analizė svarbi.
First Published Online: 16 May 2013
Reikšminiai žodžiai: plieninis rėmas, plastiškumas, gniuždoma kolona, lenkiama kolona, statika, dinamika |
| first_indexed | 2024-12-14T02:16:50Z |
| format | Article |
| id | doaj.art-2cac190232a840458907c308ba2c69a6 |
| institution | Directory Open Access Journal |
| issn | 2029-882X 2029-8838 |
| language | English |
| last_indexed | 2024-12-14T02:16:50Z |
| publishDate | 2010-09-01 |
| publisher | Vilnius Gediminas Technical University |
| record_format | Article |
| series | Engineering Structures and Technologies |
| spelling | doaj.art-2cac190232a840458907c308ba2c69a62022-12-21T23:20:37ZengVilnius Gediminas Technical UniversityEngineering Structures and Technologies2029-882X2029-88382010-09-012310.3846/skt.2010.14Plastic deformations of steel frame: statics and dynamicsVytautas Kargaudas0Nerijus Adamukaitis1Kauno technologijos universitetas, Studentų g. 48, LT-51367 Kaunas, LietuvaKauno technologijos universitetas, Studentų g. 48, LT-51367 Kaunas, LietuvaWhen all deformations of a column are elastic, transverse deflections of the column depend on transverse force and axial displacements depend on axial force only. These classical dependences are unsuitable for elastic-plastic deformations. Plastic deformations develop in columns when steel frame is influenced by extreme action. When a steel column is in the elastic-plastic state, the distribution of elastic and plastic deformations in the cross-section depends on both the bending moment and compressing force. The ideal elastic-plastic material is assumed in this investigation (Prandtl stress – strain diagram). If the shape of the column section is double tee, flange width is neglected with respect to web height, but the area of the flange cross-section is assumed a constant. Single-sided or double-sided yield depends on the moment and force, and therefore curvature and the axial strain of the column can be calculated when yielding dependences are determined. Transverse and axial displacements of the highest point of the column are deduced by integration and depend on two arguments: bending force and axial force. These dependences are essentially non-linear, so linear approximations can be assessed for some vicinity of axial force and bending moment values. When axial force is a constant and transverse force increases, both axial and transverse displacements tend to increase. If transverse force is a constant and axial force increases, both displacements increases but dependence lines remain different and depend on cross-section shape parameter equal to the ratio of the flange area and the area of the whole cross-section. A distinguished feature of plastic deformations is dependence on the history of loading a frame of which can be selected in an arbitrary way by an investigator if a quasi-static solution is under examination. The loading of a frame and inertia forces have to be deduced if dynamic analysis is studied. Not only the ultimate result but also the way of approaching a plastic piston – plastic hinge is important. The bended and compressed column is the structure when inelastic dynamic analysis is really important. Plieninio rėmo plastinės deformacijos: statika ir dinamika Santrauka Plastinės deformacijos atsiranda, kai plieninį rėmą veikia ekstremalios apkrovos. Jei plieninėje kolonoje yra tampriosios ir plastinės deformacijos, tai įtempių išsidėstymas skerspjūvyje priklauso nuo lenkimo momento ir gniuždymo jėgos. Vienpusis arba dvipusis takumas priklauso nuo momento ir ašinės jėgos, todėl kolonos kreivis ir ašinė santykinė deformacija gali būti apskaičiuoti, kai takumo priklausomybės nustatytos. Aukščiausio kolonos taško ašinis ir skersinis poslinkiai apskaičiuojami integruojant ir priklauso nuo dviejų argumentų: lenkimo jėgos ir gniuždymo jėgos. Svarbi savybė, susijusi su plastinėmis deformacijomis, yra jų priklausomybė nuo apkrovimo istorijos, t. y. nuo apkrovimo eigos. Jei tiriamoji problema yra kvazistatinė, tai apkrovimo eiga gali būti paties tyrėjo laisvai parenkama. Jei tiriama plieninio rėmo dinamika, tai rėmo apkrova, inercijos jėgos turi būti atrasti. Ne tik ribinė reikšmė, bet ir artėjimo kelias prie plastinio stūmoklio – plastinio lanksto – turi būti atrastas ir yra svarbus. Lenkiama ir gniuždoma kolona yra viena iš konstrukcijų, kuriai dinaminė analizė svarbi. First Published Online: 16 May 2013 Reikšminiai žodžiai: plieninis rėmas, plastiškumas, gniuždoma kolona, lenkiama kolona, statika, dinamikahttps://www.bme.vgtu.lt/index.php/EST/article/view/7519steel frameplasticitycompressed columnbended columnstaticsdynamics |
| spellingShingle | Vytautas Kargaudas Nerijus Adamukaitis Plastic deformations of steel frame: statics and dynamics Engineering Structures and Technologies steel frame plasticity compressed column bended column statics dynamics |
| title | Plastic deformations of steel frame: statics and dynamics |
| title_full | Plastic deformations of steel frame: statics and dynamics |
| title_fullStr | Plastic deformations of steel frame: statics and dynamics |
| title_full_unstemmed | Plastic deformations of steel frame: statics and dynamics |
| title_short | Plastic deformations of steel frame: statics and dynamics |
| title_sort | plastic deformations of steel frame statics and dynamics |
| topic | steel frame plasticity compressed column bended column statics dynamics |
| url | https://www.bme.vgtu.lt/index.php/EST/article/view/7519 |
| work_keys_str_mv | AT vytautaskargaudas plasticdeformationsofsteelframestaticsanddynamics AT nerijusadamukaitis plasticdeformationsofsteelframestaticsanddynamics |