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Research BTM

The beam-truss model (BTM) is an accurate and computationally efficient seismic analysis method for RC walls and other components as well as for entire building and structural systems that has been developed over the last fifteen years resulting in numerous peer-reviewed and other publications with the most important features of these publications summarized in Table 1. The BTM has been extensively validated using the experimental test results of twenty-eight (28) RC specimens mostly structural walls of various section shapes and configurations including rectangular (R) and barbell (B) sections, flanged walls of various sectional shapes (T, Ɪ, C, H) and coupled walls via coupling beams and/or slabs. The BTM has also been used to model shear-critical RC columns and this publication was used from one of the winners of the 2021 PEER’s blind prediction contest of a shear-critical RC column. The BTM in FE-Multiphys won the 2022 UCLouvain Blind Prediction Competition on the Cyclic Response of RC U-shaped Walls.  The BTM has also been used to efficiently simulate the seismic response of entire RC wall buildings considering the nonlinearity of all structural members. Finally, the BTM has captured the experimentally tested behavior of reinforced masonry walls as well as of masonry infilled RC frames. More information regarding the BTM are found in the BTM Component ReportMore information on the beam-truss model (BTM) in FE-Multiphys computational framework for the seismic analysis of reinforced concrete wall buildings are found here

Table 1. Overview of the peer-reviewed and key conference publications using the nonlinear cyclic truss and BTM

BTM references Table.png

Publications on Truss and Beam-Truss Model (BTM) 

Publications BTM
  1. Alvarez R., Restrepo JI, Panagiotou M (2019). Nonlinear Cyclic Beam Truss Model for Analysis of Reinforced Concrete Coupled Structural Walls, Bull. Earthq. Eng., 17(11), https://doi.org/10.1007/s10518-019-00639-8.

  2. Alvarez R., Restrepo JI, Panagiotou M, Godinez S (2020a). Analysis of Reinforced Concrete Coupled Structural Walls Via the Beam-Truss Model, Engineering Structures. Link

  3. Alvarez R., Restrepo JI, Panagiotou M. (2020b). Plastic Hinge Out-of-Plane Buckling in Structural Walls - Analysis Using the Beam-Truss Model, ASCE, J. Struct. Eng., in press.

  4. Deng X., Koutromanos I., Murcia-Delso J., Panagiotou M. (2021). Nonlinear Truss Models for Strain-based Seismic Evaluation of Planar RC Walls. Earthquake Engineering and Structural Dynamics. Free access link

  5. Deng X., Murcia-Delso J., Koutromanos I.,  Panagiotou M. (2022). Nonlinear truss modeling and strain-based evaluation of RC walls considering lap-splice failure effects . 3rd European Conference on Earthquake Engineering & Seismology, Bucharest, Romania.

  6. Ioannis Koutromanos, Marios Mavros, Marios Panagiotou, Jose I. Restrepo & Rodolfo Alvarez. (2022). Computational Performance Assessment and Failure Analysis of Reinforced Concrete Wall Buildings Under Seismic Loads, RILEM International Conference on Numerical Modeling Strategies for Sustainable Concrete Structures, SSCS 2022: Numerical Modeling Strategies for Sustainable Concrete Structures pp 187–196. 

  7. Lu Y, Panagiotou M (2015). Earthquake Damage Resistant Tall Buildings at Near Fault Regions Using Base Isolation and Rocking Core Walls. Proceedings, Structures Congress, Portland, OR. Link

  8. Lu Y, Panagiotou M. (2014). Three-Dimensional Nonlinear Cyclic Beam-Truss Model for Reinforced Concrete Non-Planar Walls. ASCE, J. Struct. Eng., 140(3), http://dx.doi.org/10.1061/(ASCE)ST.1943-541X.0000852.

  9. Lu Y, Panagiotou M, Koutromanos I (2014). Three-Dimensional Beam-Truss Model for RC Walls and Slabs Subjected to Cyclic Static or Dynamic Loading. PEER Report No. 2014/18, Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA.

  10. Lu. Y, Panagiotou M, and Koutromanos I. (2016). “Three-dimensional beam-truss model for RC walls and slabs, Part I: Model Description and Validation for Individual Walls. Earthq.Eng. Struct. Dyn., 45(4): 1495–1513, http://onlinelibrary.wiley.com/doi/10.1002/eqe.2719/full.

  11. Lu Y, Panagiotou M (2016). Three-Dimensional Beam-Truss Model for RC Walls and Slabs, Part II: Model Description and Validation for Coupled Walls and Slabs. Earthq.Eng. Struct. Dyn., 45(11): 1707–1724, http://onlinelibrary.wiley.com/doi/10.1002/eqe.2720/full.

  12. Mavros M, Panagiotou M, Koutromanos I, Alvarez R, Restrepo JI. (2022). Seismic analysis of a modern 14-story reinforced concrete core wall building system using the BTM-shell methodology. Earthquake Engng Struct Dyn.  Free access link

  13. M. Mavros, M. Panagiotou, I. Koutromanos, R. Alvarez  and J. I. Restrepo. (2022). Computational Fully Nonlinear Seismic Performance Investigation of a Modern 14-story Core Wall Building in Los Angeles. 12th National Conference on Earthquake Engineering, Salt Lake City, Utah.

  14. Mavros M., Panagiotou M., Koutromanos I., Restrepo J., Alvarez R. (2022). Fully Nonlinear Performance-based Seismic Analysis of a Modern RC Core Wall Building in Los Angeles Using the BTM-shell Methodology. 3rd European Conference on Earthquake Engineering & Seismology, Bucharest, Romania.

  15. Moharrami M, Koutromanos I, Panagiotou ., Girgin SC (2014). Analysis of Shear-Dominated RC Columns Using the Nonlinear Truss Analogy. Earthq. Eng. Struct. Dyn., 44(5): 677–694, http://dx.doi.org/10.1002/eqe.2480

  16. Moharrami M., Koutromanos I., Panagiotou M. (2015). Nonlinear Truss Modeling Method for the Analysis of Shear Failures in Reinforced Concrete and Masonry Structures. Proceedings, ATC&SEI 2nd Conference on Improving the Seismic Performance of Existing Buildings and Other Structures, December, San Francisco. CA.

  17. Panagiotou M. (2008). Seismic Design, Testing, and Analysis of Reinforced Concrete Wall Buildings. PhD Thesis. University of California San Diego. La Jolla, California. 

  18. Panagiotou M., Restrepo JI, Schoettler M, Geonwoo K (2012). Nonlinear Truss Model for Reinforced Concrete Walls. ACI Struct. J., 109(2): 205–214. http://dx.doi.org/10.14359/51683631

  19. Panagiotou M., Koutromanos I., Mavros M., Deng X., Alvarez R., Restrepo J.I., Murcia-Delso J., Acero G. (2021). Nonlinear Beam-Truss Model (BTM) for Seismic Performance Evaluation of Reinforced Concrete Wall Buildings. 2021 SEAOC Convention Proceedings, San Diego, California.

  20. Panagiotou M., Mavros M., Koutromanos I., Alvarez R., Restrepo J., Acero G., Tunick D., Kirkpatrick D., Wilkerson R., Hata O., Gemmill M. (2022). Evaluation of Standard Nonlinear Seismic Analysis for a Modern Concrete Core Wall Building in Los Angeles, SEAOC Convention. Indian Wells.

  21. Salinas D., Koutromanos I., and Leon R. (2022). Nonlinear truss modeling method for masonry-infilled reinforced concrete frames. Engineering Structures.

  22. Zhang P, Restrepo JI, Conte JP, Ou J. (2017). Nonlinear Finite Element Modeling and Response Analysis of the Collapsed Alto Rio Building in the 2010 Chile Maule Earthquake. Struct. Des. Tall Spec. Build., 207;26. doi:10.1002/tal.1364.

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