Development of a portable mechanical hysteresis measurement and imaging system for impact characterization in honeycomb sandwich structures

Thumbnail Image
Date
2010-07-01
Authors
Barnard, Daniel
Hsu, David
Major Professor
Advisor
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Authors
Research Projects
Organizational Units
Organizational Unit
Center for Nondestructive Evaluation

The Center for Nondestructive Evaluation at Iowa State has been involved in the use of nondestructive evaluation testing (NDT) technologies to: assess the integrity of a substance, material or structure; assess the criticality of any flaws, and to predict the object’s remaining serviceability. NDT technologies used include ultrasonics and acoustic emissions, electromagnetic technologies, computer tomography, thermal imaging, and others.

History
In October of 1985 the CNDE was approved by the State Board of Regents after it had received a grant from the National Science Foundation (NSF) as an Industry/University Cooperative Research Center.

Journal Issue
Is Version Of
Versions
Series
Department
Center for Nondestructive Evaluation
Abstract

Honeycomb sandwich materials are commonly used for aero‐structures, but because the outer skins are typically thin, 2–10 plys, the structures are susceptible to impact damage. NDI methods such as tap tests, bond testers and TTU ultrasound are successfully deployed to find impact damage, but identifying the type∕degree of damage is troublesome. As the type∕degree of impact damage guides decisions by the maintenance, repair and overhaul (MRO) community regarding repair, the ability to characterize impacts is of interest. Previous work demonstrated that additional impact characterization may be gleaned from hysteresis loop area, as determined from an out‐of‐plane load‐vs‐displacement plot, where this parameter shows a correlation with impact energy. This presentation reports on current work involving the development of a portable hysteresis measurement and imaging system based on an instrumented tapper. Data processing and analysis methods that allow production of the load∕displacement data from a single accelerometer are discussed, with additional reporting of tests of software to automatically vary pixel size during scanning to decrease C‐scans inspection time.

Comments

Copyright 2011 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.

This article appeared in AIP Conference Proceedings 1335 (2011): 1743–1750 and may be found at http://dx.doi.org/10.1063/1.3592139.

Description
Keywords
Citation
DOI
Source
Copyright
Sat Jan 01 00:00:00 UTC 2011