Estimation of semi-rigid joints by cross modal strain energy method

다국어 초록 (Multilingual Abstract)

We present a semi-rigid connection estimation method by using cross modal strain energy method. While rigid or pinned assumptions are adopted for steel frames in traditional modeling via finite element method, the actual behavior of the connections is usually neither. Semi-rigid joints enable connections to be modeled as partially restrained, which improves the quality of the model. To identify the connection stiffness and update the FE model, a newly-developed cross modal strain energy (CMSE) method is extended to incorporate the connection stiffness estimation. Meanwhile, the relations between the correction coefficients for the CMSE method are derived, which enables less modal information to be used in the estimation procedure. To illustrate the capability of the proposed parameter estimation algorithm, a four-story frame structure is demonstrated in the numerical studies. Several cases, including Semi-rigid joint(s) on single connection and on multi-connections, without and with measurement noise, are investigated. Numerical results indicate that an excellent updating is achievable and the connection stiffness can be estimated by CMSE method.

참고문헌 (Reference)

1 Hasan N. Katkhuda, "System identification of steel framed structures with semi-rigid connections" 국제구조공학회 34 (34): 351-366, 2010

2 Chen, W.F, "Stability Design of Steel Frames" CRC Press Inc 1991

3 Sanayei, M., "Parameter estimation incorporating modal data and boundary conditions" 125 (125): 1048-1055, 1999

4 Mottershead, J.E, "Model updating in structural dynamics : asurvey" 167 : 347-376, 1993

5 Wang,S, "Model updating and parameters estimation incorporating flexible joints and boundary conditions" 2013

6 Ewins, D. J., "Modal Testing: Theory, Practice and Application, 2nd Edition" Research Studies Press 2000

7 Monforton, G.R, "Matrix analysis of semi-rigidly connected frames" 89 (89): 13-42, 1963

8 Friswell, M.I., "Finite Element Model Updating In Structural Dynamics" Kluwer Academic Publishers 1995

9 Fan, F., "Experimental study of semi-rigid joint systems subjected to bending with and without axial force" 68 : 126-137, 2012

10 Loureiro, A., "Experimental and numerical analysis of three-dimensional semi-rigid steel joints under non-proportional loading" 38 : 68-77, 2012

11 Cunha, J., "Evaluation of stiffness of semi-rigid joints in pultruded profiles from dynamic and static data by using model updating technique" 30 (30): 1024-1036, 2008

12 Hadianfard, M.A., "Effects of semi-rigid behavior of connections in the reliability of steel frames" 25 : 123-138, 2003

13 Wang, S., "Damage detectionin offshore platform structures from limited modal data" 41 : 48-56, 2013

14 Hu, S. L. J., "Cross-model cross-mode method for model updating" 21 (21): 1690-1703, 2007

15 Hu, S. L. J., "Cross modal strain energy method for estimating damage severity" 132 (132): 429-437, 2006

16 Wang, S., "Cross modal strain energy method for damage localization and severity estimation" 2 : 245-249, 2007

17 Loureiro, A., "Axial stiffness prediction of non-preloaded T-stubs : an analytical frame approach" 66 : 1516-1522, 2010

18 Daniunas, A, "Analysis of the steel frames with the semi-rigid beam-to-beam and beam-to-column knee joints under bending and axialforces" 30 : 3114-3118, 2008