Effect of welding residual stress on natural frequencies using experimental and numerical analysis

Authors

Professor of Mechanical Engineering Department, K.N. Toosi University of Technology, Tehran, Iran

Abstract

The manufacturing processes mostly generate residual stresses in structures. Welding as well, can cause these types of stresses which can be useful or detrimental in different cases. Expensive and time-consuming tests should be conducted to measure residual stresses, however, modal testing is widely available providing results conveniently and quickly. In cases in which the qualitative changes in stress is required, experimental modal testing is a suitable substitute for residual stress measurement processes. In this paper, experimental modal analysis have been conducted on an aluminum specimen, also the same procedure has been done on welded specimens. Natural frequencies are compared before and after the welding along with verification of experimental modal analysis integrity using Euler-Bernoulli relations. In addition to experimental modal analysis, finite element modeling of welding process has been done comparing the numerical and experimental results. The results obtained from the investigation have shown that welding made the structure harder leading to elevation of its natural frequencies. This increase in frequencies are associated with residual stresses generated in welding process. By comparing natural frequencies of the specimens, a quantitative relation can be drawn between the residual stress caused by welding and changes of natural frequencies.

Keywords

Main Subjects


[1]  Friedman E (1975) Thermomechanical analysis of the welding process using the finite element method. J Press Vess-T ASME 97(3): 206-213.
[2] Qu L, Wei F, Huang J, Zhoa H (2013) Numerical Modal analysis for influence of initial deflection and residual stress on welded I-steel beam. JWRHE.
[3] Aykan M, Nevzat Ozguven H (2013) Topics in modal analysis, volume 7: proceedings of the 31st imac, a conference on structural dynamics. Conference Proceedings of the Society for Experimental Mechanics Series 45.
[4] Lira de Brito V, Pena AN, Pimentel RL, Vital de Brito JL (2014) Modal tests and model updating for vibration analysis of temporary grandstand. Adv Struct Eng 17(5): 721-734.
[5] Narayana KL, Jebaraj C (1999) Sensitivity analysis of local/global modal parameters for identification of a crack in a beam. J Sound Vib 228(5): 977-994.
[6] Husain NA (2011) Detection of damage in welded structure using experimental modal data. 9th International Conference on Damage Assessment of Structures (DAMAS 2011), Journal of Physics: Conference Series 305: 012120.
[7] Abdul Rani MN (2011) Model updating for a welded structure made from thin steel sheets. Appl Mech Mater 70: 117-122.
[8] Hu B, Richardson IM (2006) Mechanism and possible solution for transverse solidification cracking in laser welding of high strength aluminum alloys. Mater Sci Eng A 429: 287-294.
[9] Rao SS, Yap FF (1995) Mechanical vibrations. Vol. 4, Addison-Wesley, New York.
[10] Arthur WL (1969) Vibration of plates. NASA Pub.
[11] ASM handbook (1993) Properties and Selection nonferrous alloys and special –purpose materials. Vol. 2.
[12] Syahroni N, Hidayat MIP (2012) Numerical simulation – from theory to industry. Chapter 24, 3D finite element simulation of T-joint fillet weld: Effect of various welding sequences on the residual stresses and distortions. 585-588.
[13] Rao SS (2007) Vibration of continuous systems. Wiley.
[14] Yang YP, Jung G, Yancey R (2005) Finite Element modeling of vibration stress relief after welding. American Society of Materials.
[15] Ewins DJ (2000) Modal testing: theory, practice and application. Vol. 2, Research studies press Baldock.
[16] Sasaki K, Kishida M, Itoh T (1997) The Accuracy of residual stress measurement by the hole-drilling method. Exp Mech 37(3).
[17] Kong F, Kovacevic R (2010) 3D finite element modeling of the thermally induced residual stress in the hybrid laser/arc welding of lap joint. J Mater Process Tech 210(6): 941-950.
[18] Shiquan S, Huandong X, Lihai W (2011) The Application of modal analysis in hole-defect in lumber. Key Eng Mat 467-469: 1776-1780.
[19] Sun W (2009) Current capabilities of the thermo-mechanical modeling of welding processes. J Multiscale Modelling 01(03n04): 451-478.
[20] Khandkar H, Khan JA, Reynolds AP, MA Sutton (2006) Predicting residual thermal stresses in friction stir welded metals. J Mater Process Tech 174: 195-203.
[21] Zhu XK, Chao YJ (2002) Effects of temperature-dependent material properties on welding simulation. Comput Struct 80: 967-976.
[22] Fanous IFZ, Younan MYA, Wifi AS (2003) 3D Finite element modeling of the welding process using element birth and element movement techniques. ASME 2002 Pressure Vessels and Piping Conference: American Society of Mechanical Engineers 165-172.
[23] Chao YJ, Qi X, Tang W (2003) Heat Transfer in friction stir welding—experimental and numerical studies. J Manuf Sci E-T ASME 125: 138-145.
[24] Schellhaase M (1985) Der schweisslichtbogen ein technologisches werkzeug. VEB Verlag Technick (DVS), Berlin.
[25] Radaj D (1992) Heat effects of welding. Springer-Verlag.
[26] Murugan N, Narayanan R (2009) Finite element simulation of residual stresses and their measurement by contour method. Mater Design 30: 2067-2071.
[27] Aoki S, Nishimura T, Hiroi T, Hirai S (2007) Reduction method for residual stress of welded joint using harmonic vibrational load. Nucl Eng Des 237: 206-212.
[28] Buschow KHJ, Cahn RW (2005) Residual stresses and distortion in welds, encyclopedia of materials: Science and Technology. Elsevier.