Inverse Sub‐structuring Method for Rigidly Coupled Product Transport System based on Frequency Response Function Testing Probe Technique

Abstract

The inverse sub-structuring method has been recently proposed and applied for inverse analysis of product transport system, to predict the component-level frequency response functions (FRFs) and the coupling dynamic stiffness from only the system-level FRFs. However, previous applications of this method were all developed based on the assumption that the components were coupled by flexible couplings. Actually, increasing more components are welded or bolted to construct a coupled system, which should be treated as rigidly coupled system. The aim of this paper is to derive a new FRF-based inverse sub-structuring method for the analysis of the dynamic characteristics of a two-component coupled product transport system with rigid couplings. And then a so-called FRF testing probe technique is proposed and applied to measure the difficult-to-monitor FRFs at the coupling interface. The developed method is verified by a lumped-mass model, showing exact agreement. Finally, the experiment on a physical prototype of two-substructure coupled product transport system is performed to further check the accuracy of the suggested method. The proposed method is an extension of previous inverse sub-structuring method and may help to obtain the main controlling factors and contributions from the various structure-borne paths for product transport system.

Analysis of Vibration Transmission Path in Packaging System and Design of Teaching Experiment

“…Te cushioning area of each part is mostly uniformly distributed in the local cushioning, which needs to improve the utilization rate of cushioning materials. Te research points of the vibration transmission characteristics (VTC) of product packaging systems [3] under actual environmental excitation have more advantages compared to the DCCC method [4,5]. Te VTC analyzes the critical vibration transmission path of the product and carries out essential bufer design for it.…”

Inverse Sub-structuring Method for Multi-coordinate Rigidly Coupled Product Transport System based on a Novel Shearing Probe Technique

“…Furthermore, the dummy mass method 12 and the probe technique method 13 were suggested recently to perform an inverse analysis of the product transport system, of which the probe technique method has great privilege in engineering applications due to the flexibility of the probe, and the negative effect of which can be easily eliminated, as claimed by the authors. 13 However, when the accessible space between the components is not large enough for mounting the probe as shown in Figure 1a, the traditional FRF probe technique will be not valid because of the difficulties of excitation as well. Moreover, the previous prove technique method may be more suitable for single-coordinate coupled product transport system.…”

“…Most product transport system should be treated as multi-coordinated coupled system, 14 and also the joints between the components should not only be modelled as flexible stiffness. 13 In this paper, the inverse sub-structuring method for multi-coordinate rigidly coupled product transport system will be developed first, and then, a new shearing probe technique which can avoid the space constraint as shown in Figure 1b is suggested to obtain the auto FRFs and cross FRFs. Finally, an experiment is carried out to validate the presented method.…”

“…Instead of using only system‐level FRFs, the indirect method suggested to obtain the coupling stiffness and component FRFs from that of easy‐to‐monitor degree of freedoms (DOFs), which would avoid the difficulties of vibration excitation and measurement because of space limitation. Furthermore, the dummy mass method and the probe technique method were suggested recently to perform an inverse analysis of the product transport system, of which the probe technique method has great privilege in engineering applications due to the flexibility of the probe, and the negative effect of which can be easily eliminated, as claimed by the authors . However, when the accessible space between the components is not large enough for mounting the probe as shown in Figure a, the traditional FRF probe technique will be not valid because of the difficulties of excitation as well.…”

“…Moreover, the previous prove technique method may be more suitable for single‐coordinate coupled product transport system. Most product transport system should be treated as multi‐coordinated coupled system, and also the joints between the components should not only be modelled as flexible stiffness …”