A reflection on the application of vibration tests for the assessment of cracking in PRC/RC beams

Abstract Occurrence of cracking damage in a structural, reinforced, concrete element leads to changes in its dynamic response. Nevertheless, the typical non-linear behavior of prestressed reinforced concrete (PRC) and reinforced concrete (RC) beams is characterized by cracking, due to the low tensile strength of concrete. It is necessary to take adequate account of cracking effects, in vibration-based monitoring of PRC/RC beams’ structural health, by distinguishing cracking of tensile concrete due to bending moment under service loads; which does not reduce the structural availability of beams although it modifies their dynamic response, from real damage deriving from defects, loss of integrity and cracking due to overloading during service life. This paper deals with cracking effects through an investigation of PRC/RC beam models in real scale, subjected to increasing static loading and natural vibration tests. Degradation of stiffness and development of cracking were related to frequency values measured in a frequency range through vibration tests on free end beams. The results are compared with theoretical values and discussed.

[1]  Zsolt Huszár.  Vibrations of cracked reinforced and prestressed concrete beams , 2008 .

[2]  Arun Kumar Pandey,et al.  Damage detection from changes in curvature mode shapes , 1991 .

[3]  R. Capozucca,et al.  Damage assessment in PRC and RC beams by dynamic tests , 2011 .

[4]  D. Zimmerman,et al.  Structural damage detection using a minimum rank update theory , 1994 .

[5]  M. N. Cerri,et al.  IDENTIFICATION OF DAMAGE IN REINFORCED CONCRETE BEAMS SUBJECTED TO CORROSION , 2000 .

[6]  Yeoshua Frostig,et al.  Natural frequencies of bonded and unbonded prestressed beams-prestress force effects , 2006 .

[7]  Geoffrey Barratt Warburton.  The dynamical behaviour of structures , 1976 .

[8]  A. S. J. Swamidas,et al.  Crack identification in vibrating beams using the energy method , 2001 .

[9]  M. Yuen.  A NUMERICAL STUDY OF THE EIGENPARAMETERS OF A DAMAGED CANTILEVER , 1985 .

[10]  Jaycee H. Chung,et al.  DETECTING STRUCTURAL DAMAGE USING FREQUENCY RESPONSE FUNCTIONS , 1998 .

[11]  W. Ostachowicz,et al.  Analysis of the effect of cracks on the natural frequencies of a cantilever beam , 1991 .

[12]  A. Swamidas,et al.  Identification of Cracking in Beam Structures Using Timoshenko and Euler Formulations , 2004 .

[13]  C. Pierre,et al.  Free Vibrations of Beams With a Single-Edge Crack , 1994 .

[14]  Y. Narkis.  Identification of Crack Location in Vibrating Simply Supported Beams , 1994 .

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

[16]  Robert D. Adams,et al.  The location of defects in structures from measurements of natural frequencies , 1979 .

[17]  Angel C. Aparicio,et al.  Structural Damage Identification from Dynamic‐Test Data , 1994 .

[18]  O. S. Salawu.  Detection of structural damage through changes in frequency: a review , 1997 .

[19]  A. K. Pandey,et al.  Damage Detection in Structures Using Changes in Flexibility , 1994 .

[20]  R. Capozucca,et al.  Influence of reinforcement corrosion—in the compressive zone—on the behaviour of RC beams , 2003 .

[21]  Fabrizio Vestroni,et al.  Detection of damage in beams subjected to diffused cracking , 2000 .

[22]  A. D. Kerr.  On the dynamic response of a prestressed beam , 1976 .

[23]  A. Barr,et al.  One-dimensional theory of cracked Bernoulli-Euler beams , 1984 .

[24]  H. Abdul Razak,et al.  The effect of corrosion on the natural frequency and modal damping of reinforced concrete beams , 2001 .

[25]  R. Capozucca.  Damage to reinforced concrete due to reinforcement corrosion , 1995 .