Utilization of modal stress approach in random-vibration fatigue evaluation

Random-vibration fatigue evaluation can be of considerable importance in the design phase of aerospace structures due to the severe dynamic loads in service. This paper presents the utilization of modal stress approach to the issue of structural random-vibration fatigue evaluation. Prognosis of random fatigue hotspots by using stress mode shapes is theoretically demonstrated. A two-step procedure is proposed for computational efficiency. Firstly, modal stress analysis is conducted to locate the fatigue hotspots in a dynamic structure. Secondly, the frequency domain-based approach for random fatigue evaluation is performed at these hotspots, as opposed to the computation of the entire structure as before. The capability of stress mode shapes to locate fatigue hotspots is verified by numerical investigations. The finite element model of a single-lap plate structure containing various opening holes was constructed for case study. Six elements were identified as hotspots by using modal stress distributions. Then, random responses and fatigue evaluation of the entire structure were carried out for verification. Good agreement was observed between the fatigue damage contour and the modal stress distributions, which can indicate that the critical positions predicted by stress mode shapes have good accuracy. The calculation time and storage space can be significantly reduced by means of the proposed evaluation procedure. Therefore, the accuracy and efficiency of utilization of modal stress approach in random fatigue evaluation can be ensured.

[1]  S. Fawzia,et al.  An Improved Method to Detect Damage Using Modal Strain Energy Based Damage Index , 2012 .

[2]  Jwo Pan,et al.  Fatigue Testing and Analysis: Theory and Practice , 2004 .

[3]  S. Natsiavas,et al.  Dynamic Response and Identification of Critical Points in the Superstructure of a Vehicle Using a Combination of Numerical and Experimental Methods , 2015 .

[4]  Sharif Rahman,et al.  A Global–Local Approach for Mechanical Deformation and Fatigue Durability of Microelectronic Packaging Systems , 2007 .

[5]  Liu Liu,et al.  Thermal-Acoustic Fatigue of a Multilayer Thermal Protection System in Combined Extreme Environments , 2014 .

[6]  Kazimierz Sobczyk,et al.  Modelling of random fatigue crack growth , 1986 .

[7]  Tomasz Sadowski,et al.  Experimental investigations and numerical modelling of steel adhesive joints reinforced by rivets , 2010 .

[8]  Turan Dirlik,et al.  Application of computers in fatigue analysis , 1985 .

[9]  David Yoon,et al.  Fatigue life evaluation of mechanical components using vibration fatigue analysis technique , 2011 .

[10]  Marios K. Chryssanthopoulos,et al.  Numerical modelling of riveted railway bridge connections for fatigue evaluation , 2007 .

[11]  J. Wijker.  Random Vibrations in Spacecraft Structures Design , 2009 .

[12]  Janko Slavič,et al.  Frequency-domain methods for a vibration-fatigue-life estimation – Application to real data , 2013 .

[13]  A. A. Hamada,et al.  Prediction of fatigue life of glass fiber reinforced polyester composites using modal testing , 2014 .

[14]  T. Leung,et al.  THEORETICAL AND EXPERIMENTAL STUDY OF MODAL STRAIN ANALYSIS , 1996 .

[15]  L. H. Yam,et al.  Identification of damage locations for plate-like structures using damage sensitive indices: strain modal approach , 2002 .

[16]  Claudio Braccesi,et al.  Random fatigue. A new frequency domain criterion for the damage evaluation of mechanical components , 2015 .

[17]  Tomas Ireman,et al.  Three-dimensional stress analysis of bolted single-lap composite joints , 1998 .

[18]  P. R. Cunningham,et al.  A review of analytical methods for aircraft structures subjected to high-intensity random acoustic loads , 2004 .

[19]  Murat Aykan,et al.  Vibration fatigue analysis and multi-axial effect in testing of aerospace structures , 2009 .

[20]  Adam Niesłony,et al.  Fatigue life prediction for broad-band multiaxial loading with various PSD curve shapes , 2012 .

[21]  Qingguo Fei,et al.  Temperature-dependence of acoustic fatigue life for thermal protection structures , 2014 .

[22]  R Martinez-Val,et al.  Aeronautics and astronautics: Recent progress and future trends , 2009 .

[23]  Sotirios Natsiavas,et al.  Stochastic dynamics and fatigue analysis of large-scale mechanical models using multilevel substructuring , 2012 .

[24]  Junyong Tao,et al.  Fatigue reliability evaluation of structural components under random loadings , 2014 .

[25]  Bin Ma,et al.  Intelligent damage identification method for large structures based on strain modal parameters , 2014 .

[26]  Ali Fatemi,et al.  Cumulative fatigue damage and life prediction theories: a survey of the state of the art for homogeneous materials , 1998 .

[27]  N. E. Bedewi,et al.  Effect of fatigue loading on the modal properties of composite structures and its utilization for prediction of residual life , 1997 .

[28]  Damir Tadjiev,et al.  Fatigue Life Prediction under Random Loading Conditions in 7475-T7351 Aluminum Alloy using the RMS Model , 2006 .

[29]  De-Guang Shang,et al.  Fatigue damage model based on the natural frequency changes for spot-welded joints , 2008 .

[30]  Jaap Wijker,et al.  Random Vibrations in Spacecraft Structures Design: Theory and Applications , 2009 .

[31]  N. W. M. Bishop,et al.  A THEORETICAL SOLUTION FOR THE ESTIMATION OF “RAINFLOW” RANGES FROM POWER SPECTRAL DENSITY DATA , 1990 .

[32]  Wei-Xin Ren,et al.  Strain modes based dynamic displacement estimation of beam structures with strain sensors , 2014 .

[33]  S. Natsiavas,et al.  Dynamics of large scale mechanical models using multilevel substructuring , 2007 .

[34]  Roberto Tovo,et al.  Comparison of spectral methods for fatigue analysis of broad-band Gaussian random processes , 2006 .

[35]  Qingguo Fei,et al.  Evaluation of opening-hole shapes for rivet connection of a composite plate , 2017 .

[36]  Y. Y. Li,et al.  Hypersensitivity of strain-based indicators for structural damage identification: A review , 2010 .

[37]  Yingguang Wang.  Spectral fatigue analysis of a ship structural detail – A practical case study , 2010 .

[38]  C. Guedes Soares,et al.  Fatigue damage assessment of corroded oil tanker details based on global and local stress approaches , 2012 .

[39]  S. Law,et al.  Structural Damage Detection from Modal Strain Energy Change , 2000 .

[40]  Jun-hong Zhang,et al.  Numerical study on vibration stress of rotating fan blade under aerodynamic load at critical speed , 2016 .

[41]  Claudio Sbarufatti,et al.  Performance optimization of a diagnostic system based upon a simulated strain field for fatigue damage characterization , 2013 .