SAMPE Journal - July/August 2012 - (Page 5)

A Note from the Technical Director Dr. Scott W. Beckwith SAMPE Journal Technical Editor swbeckwith@aol.com Composites Design, Analysis, Structural Verification and Product Safety Assurance: A Complete Responsibility Composite product safety must always be discussed when a product is offered into the marketplace. Composite materials and the resultant structures produced using them sometimes achieve a bad name. Composite products have failed and someone was seriously hurt. In the American Airlines Flight 587 that crashed after leaving JFK Airport in November 2001, the composite tail structure tore off the plane. Instantly composite materials and structures became the focus of the investigation. Composites and their safety made front page news every time the AA587 crash was discussed by technical and non-technical people alike. In the end, after extensive testing, failure analysis and forensics to reconstruct the crash, the use of composite materials and structures were essentially exonerated. In that case, the efforts made by the plane’s manufacturer showed the extensive design, analysis, finite element analysis (FEA), safety factor, test verification, NDT results and materials certification data. In other words, the complete design and verification of the end-use product was carefully thought out and documented prior to putting the product on the market as is required by the FAA. A number of composite products on today’s market involve the safety of an end-user’s health, safety and protection. A number of composite products, while seemingly simple in their “design”, may contain deficiencies that may result in serious injury and death. Overall, the composites industry has generally been very good at developing design and analysis approaches to promote product safety and reliability. Both ASTM and the now defunct SACMA have issued a wide number of test standards aimed at assuring good product performance through rigid test practices. Regrettably, a number of companies do not use these standards or other international standards to verify material properties, material design allowables, or conduct meaningful verification tests on production products. The end result often consists of the following composite product deficiencies which tend to result in either static failures early on or in fatigue failures later: porosity, void, delaminations, waviness in fiber paths, material substitutions, inadequate joint designs, foreign objects left inside the layers, insufficient material, etc. Very often “design” to such companies mean conducting only material trade studies to select the least expensive or the lightest weight material and then throw it into a “quasiisotropic” lay-up so that no further structural analysis is then performed. Consequently many of these products do not see any further “stress or structural analysis”. They do not use safety factors. They never apply these to any measured, calculated or vendorsupplied “material allowables”. Testing often uses only a few Consumer Safety Product Commission “standards” that often do not simulate end-use structural loading or lifecycle conditions. The end result is a composite product that is tested in very limited fashion, never inspected to current industry standards, and has never been evaluated to assess either the manufacturing process deficiencies or to verify manufacturing quality in production products after testing very few prototype units. Such effort does not require extensive effort. Conducting a limited amount of simplistic design-analysis and some reasonable simulation tests, especially on high-priced consumer products – might just save a person from serious product injury or death. In many cases the industries involved often make some attempt to improve the overall design-analysisinspection-test approach to producing composite products used by the general public. In other cases the industry does not meet what we in the composites industry would expect of them. It is clearly time for industries to improve upon their composite product design and manufacturing approach. It is a sound business strategy to applying proven composites methodology to assuring safe composite products. Our industry owes our customers nothing less. SAMPE Journal, Volume 48, No. 4, July/August 2012 5 http://www.reinhold-ind.com http://www.reinhold-ind.com

Table of Contents for the Digital Edition of SAMPE Journal - July/August 2012

SAMPE Journal - July/August 2012
Table of Contents
President’s Message
Technical Director’s Corner
Development of New Lightweight Hybrid Sandwich Cores using FDM Technology
Corporate Partners
Europe News & Views
SAMPE Europe’s SETEC 2012, Lucerne
SAMPE Journal Editorial Calender
Welcome SAMPE’s Newest Members
Materials & Products
Perspectives
Perspectives–The Art of a Well-Crafted BHAG
Out-of-Autoclave Sandwich Structure: Processing Study
SAMPE LinkedIn Communities
SAMPE Proceedings
SAMPE 2013|Long Beach Call for Papers
SAMPE Tech 2012|Charleston, SC
Industry News
Composite Payload Fairing Structural Architecture Assessment and Selection
SAMPE 2012|Baltimore-A Review
SAMPE 2012|Baltimore Photo Gallery
The SAMPE Foundation
Advertiser’s Index
Resource Center
SAMPE Membership Application
SAMPE Books & CD’s Order Form
Industry Events Calendar
Chapter Meetings Dates and Contacts

SAMPE Journal - July/August 2012