Experiments on clearance identification in cantilever beams reduced from artillery mechanism

Clearances existing in artillery mechanism cause the muzzle disturbance and reduce the artillery firing accuracy. If the parameters of the clearance nonlinearity can be identified by taking advantage of the dynamic information, the quantitative relation between the clearance and muzzle disturbance can be established, and then the clearances of such nonlinear system can be controlled in a reasonable range to improve the artillery firing accuracy. This paper proposed a nonlinear identification method for the cantilever beam with clearances reduced from barrel-cradle structure. A modified restoring force surface method is proposed to identify the clearance value of the cantilever beam in time domain, and then a modified nonlinear identification through feedback of outputs method, i.e., reduced-order nonlinear identification through feedback of the output method, is proposed to recognize the related contact stiffness in frequency domain. The feasibility of the combined identification process is verified by a cantilever beam with two clearances in simulation, and a test-bed with adjusted clearance and contact stiffness which is regardless of other nonlinear factors by adjusting the position of the clearance and excitation method was designed to verify the effectiveness of this method. In the end, some influence factors of this identification process are discussed in detail. The results show that the proposed methods can identify clearance-nonlinearity parameters with high precision.

[1]  L. Garibaldi.  APPLICATION OF THE CONDITIONED REVERSE PATH METHOD , 2003 .

[2]  Mihai Dupac,et al.  Dynamic analysis of a flexible linkage mechanism with cracks and clearance , 2010 .

[3]  Gaëtan Kerschen,et al.  ECL BENCHMARK: APPLICATION OF THE PROPER ORTHOGONAL DECOMPOSITION , 2003 .

[4]  Qingkai Han,et al.  Nonlinear dynamics of a vibratory cone crusher with hysteretic force and clearances , 2011 .

[5]  Douglas E. Adams,et al.  A time and frequency domain approach for identifying nonlinear mechanical system models in the absence of an input measurement , 2005 .

[6]  D. Adams,et al.  Characterization of Nonlinear Vibrating Systems Using Internal Feedback and Frequency Response Modulation , 1999 .

[7]  Randall J. Allemang,et al.  A NEW DERIVATION OF THE FREQUENCY RESPONSE FUNCTION MATRIX FOR VIBRATING NON-LINEAR SYSTEMS , 1999 .

[8]  Jörg Wauer,et al.  Stoßsimulation mittels einseitiger Feder‐Dämpfer Kontakte , 2004 .

[9]  Luigi Garibaldi,et al.  Identification of clearance-type nonlinearities , 2008 .

[10]  Gaëtan Kerschen,et al.  Identification of a continuous structure with a geometrical non-linearity. Part I: Conditioned reverse path method , 2003 .

[11]  Rajendra Singh,et al.  IDENTIFICATION OF MULTI-DEGREE-OF-FREEDOM NON-LINEAR SYSTEMS UNDER RANDOM EXCITATIONS BY THE “REVERSE PATH” SPECTRAL METHOD , 1998 .

[12]  Luigi Garibaldi,et al.  A time domain approach for identifying nonlinear vibrating structures by subspace methods , 2008 .

[13]  Gaëtan Kerschen,et al.  VTT benchmark: Application of the restoring force surface method , 2003 .

[14]  Jean-Philippe Noël,et al.  Complex dynamics of a nonlinear aerospace structure: Experimental identification and modal interactions , 2014 .

[15]  Stefano Marchesiello.  APPLICATION OF THE CONDITIONED REVERSE PATH METHOD , 2003 .

[16]  Sami F. Masri,et al.  A Nonparametric Identification Technique for Nonlinear Dynamic Problems , 1979 .

[17]  Wei Jin,et al.  Identification of Clearance and Contact Stiffness in a Simplified Barrel-Cradle Structure of Artillery System , 2015 .

[18]  Yang Zhao,et al.  Dynamic behaviour analysis of planar mechanical systems with clearance in revolute joints using a new hybrid contact force model , 2012 .

[19]  Martin Magnevall,et al.  Nonlinear structural identification by the “Reverse Path” spectral method , 2012 .

[20]  Randall J. Allemang,et al.  A FREQUENCY DOMAIN METHOD FOR ESTIMATING THE PARAMETERS OF A NON-LINEAR STRUCTURAL DYNAMIC MODEL THROUGH FEEDBACK , 2000 .

[21]  Winson Taam,et al.  Nonlinear System Analysis and Identification From Random Data , 1991 .

[22]  Gaëtan Kerschen,et al.  THEORETICAL AND EXPERIMENTAL IDENTIFICATION OF A NON-LINEAR BEAM , 2001 .