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Abstract

The non-linear analysis of hollow-core concrete slabs requires the use of advanced numerical techniques, proper constitutive models both for concrete and steel as well as particular computational skills. If prestressing, cracking, crack opening, material softening, etc. are also to be taken into account, then the computational task can far exceed the capabilities of an ordinary engineer. In order for the calculations to be carried out in a traditional design office, simplified calculation methods are needed. They should be based on the linear finite element (FE) method with a simple approach that takes into account material nonlinearities. In this paper the simplified analysis of hollow-core slabs based on the generalized nonlinear constitutive law is presented. In the proposed method a simple decomposition of the traditional iterative linear finite element analysis and the non-linear algebraic analysis of the plate cross-section is used. Through independent analysis of the plate cross-section in different deformation states, a degraded plate stiffness can be obtained, which allows for iterative update of displacements and rotations in the nodes of the FE model. Which in turn allows to update the deformation state and then correct translations and rotations in the nodes again. The results obtained from the full detailed 3D nonlinear FEM model and from the proposed approach are compared for different slab cross-sections. The obtained results from both models are consistent.
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Authors and Affiliations

Natalia Staszak
1
ORCID: ORCID
Tomasz Garbowski
1
ORCID: ORCID
Barbara Ksit
2
ORCID: ORCID

  1. Poznan University of Life Sciences, Department of Biosystems Engineering, Wojska Polskiego 50, 60-627 Poznań
  2. Poznan University of Technology, Institute of Building Engineering, Piotrowo 5, 60-965 Poznan, Poland
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Abstract

The paper presents a modified finite element method for nonlinear analysis of 2D beam structures. To take into account the influence of the shear flexibility, a Timoshenko beam element was adopted. The algorithm proposed enables using complex material laws without the need of implementing advanced constitutive models in finite element routines. The method is easy to implement in commonly available CAE software for linear analysis of beam structures. It allows to extend the functionality of these programs with material nonlinearities. By using the structure deformations, computed from the nodal displacements, and the presented here generalized nonlinear constitutive law, it is possible to iteratively reduce the bending, tensile and shear stiffnesses of the structures. By applying a beam model with a multi layered cross-section and generalized stresses and strains to obtain a representative constitutive law, it is easy to model not only the complex multi-material cross-sections, but also the advanced nonlinear constitutive laws (e.g. material softening in tension). The proposed method was implemented in the MATLAB environment, its performance was shown on the several numerical examples. The cross-sections such us a steel I-beam and a steel I-beam with a concrete encasement for different slenderness ratios were considered here. To verify the accuracy of the computations, all results are compared with the ones received from a commercial CAE software. The comparison reveals a good correlation between the reference model and the method proposed.
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Bibliography


[1] Abaqus Documentation Collection, Abaqus Analysis User's Manual, Abaqus/CAE User's Manual, 2020.
[2] A. M. Barszcz, “Direct design and assessment of the limit states of steel planar frames using CSD advanced analysis”, Archives of Civil Engineering, 64(4), pp. 203–241, 2018. https://doi.org/10.2478/ace-2018-0071
[3] S. El-Tawil, C. F. Sanz-Picon, G. G. Deierlein, „Evaluation of ACI 318 and AISC (LRFD) strength provisions for composite beam-columns”, Journal of Constructional Steel Research, 34(1): pp 103–123, 1995.
[4] K. A. Farhan, M. A. Shallal, „Experimental behaviour of concrete-filled steel tube composite beams”, Archives of Civil Engineering, 66(2), pp. 235–252, 2020. https://doi.org/10.24425/ace.2020.131807
[5] T. Gajewski, T. Garbowski, „Calibration of concrete parameters based on digital image correlation and inverse analysis”, Archives of Civil and Mechanical Engineering, 14, pp. 170–180, 2014. https://doi.org/10.1016/J.ACME.2013.05.012
[6] T. Gajewski, T. Garbowski, „Mixed experimental/numerical methods applied for concrete parameters estimation”, Recent Advances in Computational Mechanics: proceedings of the 20th International Conference on Computer Methods in Mechanics (CMM 2013), Poznan, August, 2013, Editors: T. Łodygowski, J. Rakowski, P. Litewka, CRC Press/Balkema, pp. 293–302, 2014. https://doi.org/10.1201/B16513
[7] T. Garbowski, G. Maier, G. Novati, “Diagnosis of concrete dams by flat-jack tests and inverse analyses based on proper orthogonal decomposition”, Journal of Mechanics of Materials and Structures, 6 (1–4), pp. 181–202, 2011. https://doi.org/10.2140/JOMMS.2011.6.181
[8] B. Grzeszykowski, E. Szmigiera, „Nonlinear longitudinal shear distribution in steel-concrete composite beams”, Archives of Civil Engineering, 65(1), pp. 65–82, 2019. https://doi.org/10.2478/ace-2019-0005
[9] T. Jankowiak, T. Łodygowski, „Identification of parameters of concrete damage plasticity constitutive model”, Foundations of Civil and Environmental Engineering, No. 6, pp. 53–69, 2005.
[10] V. Jayanthi, C. Umarani, „Performance evaluation of different types of shear connectors in steel-concrete composite construction”, Archives of Civil Engineering, 64(2), pp. 97–110, 2018. https://doi.org/10.2478/ace-2018-0019
[11] T. Łodygowski, „Geometrycznie nieliniowa analiza sztywno-plastycznych i sprężysto-plastycznych belek i ram płaskich”, Warsaw, 1982.
[12] T. Łodygowski, M. Szumigała, „Engineering models for numerical analysis of composite bending members”, Mechanics of Structures and Machines, 20, pp. 363–380, 1992.
[13] S. A. Mahin, V. V. Bertero, RCCOLA, „a Computer Program for Reinforced Concrete Column Analysis: User's Manual and Documentation”, Department of Civil Engineering, University of California, 1977.
[14] S. A. Mirza, B. W. Skrabek, „Reliability of short composite beam-column strength interaction”, Journal of Structural Engineering, 117(8): pp 2320–2339, 1991.
[15] PN-EN 1992-1-1:2008 - Eurocode 2: Design of concrete structures - Part 1-1: General rules, and rules for buildings, 2008.
[16] G. Rakowski, Z. Kasprzyk, „Metoda Elementów Skończonych w mechanice konstrukcji”, OWPW, Poland, 2016.
[17] C. N. Reid, „Deformation geometry for materials scientists”, Pergamon, 1973.
[18] J. Rotter, P. Ansourian, „Cross-section behaviour and ductility in composite beams”, 1978.
[19] J. Siwiński, A. Stolarski, „Homogeneous substitute material model for reinforced concrete modeling”, Archives of Civil Engineering, 64(1), pp. 87–99, 2018. https://doi.org/10.2478/ace-2018-0006
[20] P. Szeptyński, „Teoria sprężystości”, Cracow, 2018.
[21] M. Szumigała, „Zespolone stalowo-betonowe konstrukcje szkieletowe pod obciążeniem doraźnym”, Wydawnictwo Politechniki Poznańskiej, Poland, 2007.
[22] A. Zirpoli, G. Maier, G. Novati, T. Garbowski, „Dilatometric tests combined with computer simulations and parameter identification for in-depth diagnostic analysis of concrete dams”, Life-Cycle Civil Engineering: proceedings of the 1st International Symposium on Life-Cycle Civil Engineering (IALCCE '08), Varenna, Lake Como, June, 2008, Editors: F. Biondini, D. M. Frangopol, CRC Press, 1, pp. 259–264, 2008. https://doi.org/10.1201/9780203885307
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Authors and Affiliations

Damian Mrówczyński
1
ORCID: ORCID
Tomasz Gajewski
2
ORCID: ORCID
Tomasz Garbowski
3
ORCID: ORCID

  1. Research and Development Division, FEMAT Sp. z o.o., Romana Maya 1, 61-371, Poznan, Poland
  2. Poznan University of Technology, Institute of Structural Analysis, Piotrowo 5, 60-965 Poznan, Poland
  3. Poznan University of Life Sciences, Department of Biosystems Engineering, Wojska Polskiego 50, 60-627 Poznan, Poland
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Abstract

In recent years, a growing problem of water deficit has been observed, which is particularly acute for agriculture. To alleviate the effects of drought, hydrogel soil additives – superabsorbent polymers (SAPs) – can be helpful.
The primary objective of this article was to present a comparison of the advantages resulting from the application of synthetic or natural hydrogels in agriculture. The analysis of the subject was carried out based on 129 articles published between 1992 and 2020. In the article, the advantages of the application of hydrogel products in order to improve soil quality, and crop growth.
Both kinds of soil amendments (synthetic and natural) similarly improve the yield of crops. In the case of natural origin polymers, a lower cost of preparation and a shorter time of biodegradation are indicated as the main advantage in comparison to synthetic polymers, and greater security for the environment.
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Authors and Affiliations

Beata Grabowska-Polanowska
1
ORCID: ORCID
Tomasz Garbowski
1
ORCID: ORCID
Dominika Bar-Michalczyk
1
ORCID: ORCID
Agnieszka Kowalczyk
1
ORCID: ORCID

  1. Institute of Technology and Life Sciences – National Research Institute, Falenty, Hrabska Av. 3, 09-090 Raszyn, Poland
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Abstract

Water erosion in mountainous areas is a major problem, especially on steep slopes exposed to intense precipitation. This paper presents the analysis of the topsoil loss using the SWAT (Soil and Water Assessment Tool) model. The SWAT model is a deterministic catchment model with a daily time step. It was designed to anticipate changes taking place in the catchment area, such as climate change and changes in land use and development, including the quantity and quality of water resources, soil erosion and agricultural production. In addition to hydrological and environmental aspects, the SWAT model is used to address socio-economic and demographic issues, such as water supply and food production. This program is integrated with QGIS software. The results were evaluated using the following statistical coefficients: determination (R2), Nash–Sutcliff model efficiency ( NS), and percentage deviation index ( PBIAS). An assessment of modelling results was made in terms of their variation according to different land cover scenarios. In the case of the scenario with no change in use, the average annual loss of topsoil (average upland sediment yield) was found to be 14.3 Mg∙ha –1. The maximum upland sediment yield was 94.6 Mg∙ha –1. On the other hand, there is an accumulation of soil material in the lower part of the catchment (in-stream sediment change), on average 13.27 Mg∙ha –1 per year.
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Authors and Affiliations

Agnieszka W. Kowalczyk
1
ORCID: ORCID
Beata Grabowska-Polanowska
1
ORCID: ORCID
Tomasz Garbowski
1
ORCID: ORCID
Marek Kopacz
2
ORCID: ORCID
Stanisław Lach
2
ORCID: ORCID
Robert Mazur
2
ORCID: ORCID

  1. Institute of Technology and Life Sciences – National Research Institute, Falenty, al. Hrabska 3, 05-090 Raszyn, Poland
  2. AGH University of Science and Technology, Faculty of Mining Surveying and Environmental Engineering, Department of Environmental Management and Protection, Cracow, Poland

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