A new impact testing method for efficient structural flexibility identification

The impact testing is an efficient experimental method that enables the quantitative and qualitative determination of the fatigue resistance of mono- and multilayer coatings deposited on various substrates, which was not possible with the common testing methods previously available. In this paper the experimental assessment of the fatigue resistance of coatings working under cyclic loading conditions by means of the dynamic impact testing method is presented. The fatigue failure mode, such cohesive or adhesive, of the investigated coatings is determined using scanning electron and optical microscopy, as well as EDX analysis. Critical values of the stress components, responsible for distinctive fatigue failure modes of the coating substrate system are obtained and the fatigue limits of aluminide coatings are illustrated in simple diagrams containing the impact load versus the number of successive impacts that the examined aluminide-P91 system can withstand.

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Mobile Impact Testing for Structural Flexibility Identification with only a Single Reference

Computer-Aided Civil and Infrastructure Engineering ◽

10.1111/mice.12112 ◽

2014 ◽

Vol 30 (9) ◽

pp. 703-714 ◽

Cited By ~ 13

Author(s):

J. Zhang ◽

S.L. Guo ◽

Q.Q. Zhang

Keyword(s):

Impact Testing ◽

Structural Flexibility

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Effects of Insoles and Additional Shock Absorption Foam on the Cushioning Properties of Sport Shoes

Journal of Applied Biomechanics ◽

10.1123/jab.23.2.119 ◽

2007 ◽

Vol 23 (2) ◽

pp. 119-127 ◽

Cited By ~ 18

Author(s):

Hung-Ta Chiu ◽

Tzyy-Yuang Shiang

Keyword(s):

Potential Energy ◽

Impact Energy ◽

Energy Condition ◽

Impact Testing ◽

Shock Absorption ◽

Absorption Effect ◽

Testing Conditions ◽

Testing Method

The purpose of this study was to investigate the effects of insoles and additional shock absorption foam on the cushioning properties of various sport shoes with an impact testing method. Three commercial sport shoes were used in this study, and shock absorption foam (TPE5020; Vers Tech Science Co. Ltd., Taiwan) with 2-mm thickness was placed below the insole in the heel region for each shoe. Eight total impacts with potential energy ranged from 1.82 to 6.08 J were performed onto the heel region of the shoe. The order of testing conditions was first without insole, then with insole, and finally interposing the shock absorption foam for each shoe. Peak deceleration of the striker was measured with an accelerometer attached to the striker during impact. The results of this study seemed to show that the insole or additional shock absorption foam could perform its shock absorption effect well for the shoes with limited midsole cushioning. Further, our findings showed that insoles absorbed more, even up to 24–32% of impact energy under low impact energy. It seemed to indicate that insoles play a more important role in cushioning properties of sport shoes under a low impact energy condition.

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Subspace Flexibility Identification Adaptive to Different Types of Input Forces

International Journal of Structural Stability and Dynamics ◽

10.1142/s0219455418500670 ◽

2018 ◽

Vol 18 (05) ◽

pp. 1850067 ◽

Cited By ~ 1

Author(s):

P. J. Li ◽

Q. Xia ◽

J. Zhang

Keyword(s):

Impact Test ◽

Effective Means ◽

Impact Testing ◽

Engineering Practice ◽

Subspace Identification ◽

Structural Flexibility ◽

Identification Algorithm ◽

Identification Methods ◽

Different Types ◽

The Time Domain

Impact testing is an effective means of identifying structural flexibility. However, most flexibility identification methods have strict requirements on the type of input forces. For instance, methods operated in the frequency domain may generate incorrect flexibility identification results when double or multiple clicks occur in an impact test. This article proposes a method to estimate the structural modal scaling coefficients and flexibility characteristics using a subspace identification algorithm in the time domain. The advantage of the proposed method is that it adapts to the input force type and thus has the potential to be widely used in engineering practice. Numerical and experimental examples are presented to illustrate the effectiveness and robustness of the proposed method.

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