Comparison of pseudo-acceleration spectrum obtained from linear interpolation of excitation with pseudo-acceleration spectrum obtained from interpolation with cubic spline function

Document Type : Original Article

Authors

1 Assistant Professor, Department of Civil Engineering, Faculty of Technology and the University of Qom, Qom, Iran

2 Phd student, Department of engineering, University of Qom, Qom, Iran

3 Phd student, Faculty of Civil Engineering, Babol Noshirvani University of Technology, Babol. Iran

4 Master's student in Technical and Engineering Faculty, Qom University, Qom, Iran.

Abstract

In this paper, the pseudo-acceleration spectra of the three accelerograms of El Centro, Naghan and Tabas, which were obtained by the linear interpolation method of stimulation (Jennings’s method) and also by using the cubic spline function, are compared with each other. Jennings' method is based on linear interpolation of excitation and is acceptable for short periods of time. In this research, three accelerograms of El Centro, Naghan and Tabas were considered, and their pseudo-acceleration response spectrum (base shear coefficient) was calculated for different damping values using linear interpolation method and interpolation with spline function. The considered damping were zero, two, five, ten and twenty percent. In order to determine the difference between the linear interpolation method and the spline function interpolation method, the time interval between the accelerometer points was divided into 2, 5, 10, 20, 50, 100, and 200 equal parts, respectively. Then, once with the linear interpolation method and again with the spline interpolation method, the internal points between the internal acceleration points were obtained and their pseudo-acceleration spectrum was calculated using the Jennings method and the interpolation method with the spline function. The calculation results showed that the pseudo-acceleration spectrum values calculated by the spline interpolation method in very short periods and low damping have a significant difference with the corresponding values of the pseudo-acceleration spectrum calculated by the linear interpolation method. It should be noted that the initial time interval between the accelerogram points of El Centro, Naghan and Tabas is 0.02 seconds.

Keywords

Main Subjects


[1] Chopra, A. K., (1995). Dynamics of Structures, Theory and Applications to Earthquake Engineering. Fifth Edition. Berkeley: Prentice-Hall.
[2] Hoseini Hashemi, B., Hoseini, M. and Khanlari, K., (2002). Effect of P-delta on Dynamic Analysis of
Structures, Second Order Analysis of Structures under Dynamic Loads, Journal of Seismology and
Earthquake Engineering
, Year 4, No. 4, pp. 2-10. (in Persian).
[3] Izadi-nia, M. and Jamshidi, J., (2016). Controlling the Dynamic Vibration of Adjacent Structures by
Establishing a Connection, Second International on Geotechnics and Seismic Engineering, Tabriz,
Iran.(in Persian).
[4] Esmailabadi, R., Bahar, A. and Azimi-Nejad, A., (2015). "Presentation of new relationships of hysteresis damping capacity of steel bending frames at the level of life safety performance required by direct design based on displacement", Scientific Research Quarterly of Earthquake Science and Engineering, year 3, number 4, p. 43- 59. (in Persian).
[5] Shafiee-fard, M. R., (2019). Second-order Analysis of Structures under Dynamic Loads by Jennings Numerical Method, Publisher: Moalefine Talaee. (in Persian).
[6] Chapra, S. C., and Canale, R. P., (2006). Numerical Methods for Engineers, Fifth Edition, McGraw-Hill, New York.
[7] Burden, R. L., and Faires, J. D., (2011). Numerical Analysis, Ninth Edition, Books/Cole.
[8] Naeim, F., (1996). Respnse of Instrumented Buildings to 1994 Northridge Earthquake, Draft Report CSMIP.
[9]Vamvatsikos, D., and Cornell, C. A., (2004). Applied Incremental Dynamic Analysis,Earthquake Spectra,Vol. 20, No. 2,pp. 523–553.
[10] Yu, R., Wang, R. and Zhu, C., (2013). A Numerical Method for Solving KdV Equation with Multilevel Bspline Quasi-interpolation, Applicable Analysis, Vol. 92, No. 8, pp. 1682-1690.
[11] Shojaee, S., Rostami, S. and Abbasi, A., (2015). An Unconditionally Stable Implicit Time Integration
Algorithm: Modified Quartic B-Spline Method, Computers and Structures, Vol. 153, pp. 98-111.
[12] Saffari, H., Shojaee, S., Rostami, S. and Malekinejad, M., (2014). Application of Cubic Spline on Large
Deformation Analysis of Structures, International Journal of Steel Structures, Vol. 14, No.1, pp.
165-172.
[13] Rostami, S. and Shojaee, S., (2017). A Family of Cubic B-Spline Direct Integration Algorithms with
Contorllabe Numerical Dissipation and Dispersion for Structural Dynamics, Iranian Journal of
Science and Technology, Transactions of Civil Engineering,
Vol. 42, pp. 17-32.
[14] Mohammadi Nia, M., Shojaee S. and Hamzehei-Javaran, S., (2020). A Mixed Formulation of B-Spline
and a New Class of Spherical Hankel Shape Functions for Modeling Elastostatic Problems, Applied
Mathematical Modelling
, Vol. 77, pp. 602-616.
[15] Mahdavi, S. H., Razak, H. A., Shojahee, S. and Mahdavi, M. S., (2015). A Comparative Study on
Application of Chebyshev and Spline Methods for Geometrically Non-linear Analysis of Truss
Structures, International Journal of Mechanical Sciences, Vol. 101-102, pp. 241-251.
[16] Ghazanfari, S., Hamzehei-Javaran, S., Alesadi A. and Shojaee, S., (2019). Free Vibration Analysis of
Cross-Ply Laminated Beam Structures using Refined Beam Theories and B-Spline Basis Functions,
Mechanics of Advanced Materials and Structures, pp. 467-475.
[17] Rostami, S. and Shojaee, S., (2019). Development of a Direct Integration Method on Quartic B-Spline
Collocation Method, Iranian Journal of Science and Technology, Transactions of Civil Engineering,
Vol. 43, pp. 615-636.
[18] Shahmorad, S. and Abdollahi, A., (2007). A Quadrature Free Convergent Method for the Numerical
Solution of Linear Fredholm Integral Equations Based on Hermite-Spline Interpolation, Proceeding
in Applied Mathematics and Mechanics,
Vol. 7, Issue 1, pp. 41-42.
[19] Maleknejad, K., and Derili, H., (2007). Numerical Solution of Hammerstein Integral Equatins by using
Combination of Spline-Collocation Method and Lagrange Interpolation, Applied Mathematics and
Computation,
Vol. 190, Issue 2, pp. 1557-1562.
[20] Maleknejad, K., and Derili, H., (2006). Numerical Solution of Integral Equatins by using Combination of
Spline-Collocation Method and Lagrange Interpolation, Applied Mathematics and Computation, Vol.
175, Issue 2, pp. 1235-1244.
[21] Liu, Z. W., Chen R. S. and Chen J. Q., (2008). Adaptive Sampling Cubic-Spline Interpolation Method
for Efficient Calculation of Monostatic RCS, Microwave and Optical Technology Letters, Vol. 50,
Issue 3, pp. 751-755.
[22] Zhernakov, V. S., Pavlov, V. P., and Kudoyarova, V. M., (1988). "The Enhanced Spline-Method for Numerical Results of Natural Frequencies of Beams",Procedia Engineering, Vol. 176, pp. 438-450, 2017.
[23] Iranian Code for Seismic Resistant Design of Buildings, Building and Housing Research Center,
First Edition. (in Persian).