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NASA Conference Publication 10075 M24 aa~e—M " NASA Workshop 2?” on Impact Damage “” to Composites Procof ea weorksdhopi sponnsogred sby the (NASA-CP-10075) NASA WORKSHOP ON IMPACT N9I1-29240 DAMAGE TO COMPOSITES (NASA) 476 p CSCL 110 uncles G3/24 0033454 The NASA Workshop on Impact Damage to Composites was sponsored by the Mechanics of Materials Branch of NASA Langley Research Center. The workshop was held on March 19 and 20, 1991 at Langley Research Center, Hampton, Virginia. The objective was to review technology for evaluating damage tolerance of composite structures with impact damage and identify deficiencies. The number of registered participants was 40, representing industry, government, and universities; a list is included. The participants were specialists in the field of impact damage and composites. The workshop was divided into the following five sessions: I - Impact Mechaanndi Sccalsin g II - Damage and Strength Predictions III - Standard Tests IV - Design Criteria and Certification V - Identification of Technology Deficiencies The review, which was conducted in Sessions I-IV, consisted of invited talks that covered research and development, design, and criteria. Technology deficiencies were identified and discussed in Session V. Mr. C. C. Poe, Jr. moderated the sessions. This conference publication is a compilation of the slides used by the speakers in Sessions I-IV and a List of Actions to Address Technology Deficiencies that were recommended by the participants in Session v. |- _ List of Actions to Address Technology Deficiencies ........ List of Speaaknd eAtrtensdee s .... . 2... ws ee uuueweeves Session I - Impact Mechanics and Scaling Composition and Analysis of the Impact Force Curve ........ Wade C. Jackson, U.S. Army Aerostructures Directorate, USAAR- ATVSACO M Impacting Large Composite Structures and Scaling Impact Respoannd sDameage. .. ... 5.5 © s+ © eee eee eeneenunes C. B. Madsen, M. E. Morgan, and R. J. Nuismer, Hercules Aerospace/Composite Products Effect of Low-Speed Impact Damage on Compression Loaded Composite Structures Marshall Rouse, Aircraft Structures Branch, NASA Langley Research Center (Not available for publication.) Session I] - Damage and Strength Predictions Delaminations in Composite Plates under Transverse Static OP Gees GOOER ew we ec eee eee eee eee eee eee eee. 79 Scott R. Finn and George S. Springer, Stanford University Impact Damaged Composites, Part I: — Simulation and Geremgen FeeGiesiome 2. cw ccc cece ee eee eee eee eee 111 Larry B. Ilcewicz and Ernest F. Dost, Boeing Commercial Airplane Group Towards a Methodology for the Assessment of Impact of Gempesice Sesmeemmes «ec ccc cece eee ee eee eee eee 163 Paul A. Lagace, Massachusetts Institute of Technology SesII]s _- Sitanodardn Te sts Standard Impact Tests Used at Lockheed ..... 2. 6 ss ew uwuse 211 Cc. E. Griffir. and T. Gillette, Lockheed Aeronautical Systems Co. Impact Damaged Composites, Part II: Standard Tests for Fuselage Structural Issues .... 1. s+ es see eee eeneunnens Ernest F. Dost and William B. Avery, ‘Boeing Commercial Airplane Group Impact Resistance and Material Toughness ..2. .«© ss .ee uee 319 John Masters, ‘ockheed Engineering & Sciences Co. iii PRECPAGEE BDLANIK NNOT FGILM ED ‘i Standard Impact Tests Damage Tolerance of Composites Criteria and Evaluation Ray E. Horton, Boeing Commercial Airplane Croup iv General Standardize philosophy of distinguishing between damage resistance and damage tolerance. Standardize coupon type impact test. Develop methodology to relate results from standard impact tests of coupons to structures. Develop analyses to reduce the amount of testing currently used in the building block approach to verify ea design. Develop progressive damage analyses. Address unique requirements of fuselage type structure. Damage Resistance Develop a measure of extent and degree of impact damage, particularily one that relates to a threshold for detection. Develop understanding of strain-rate effects. Develop failure criteria to predict damage. Determine preload effects. Develop method to predict delamination growth in fatigue. Determine residual stress effects. Develop relationship between ply cracking, interlaminar toughness, and damage resistance. Develop local contact stiffness relationship that accounts for damage and other nonlinearities. Damage Tolerance Develop failure criteria. Determine effects of biaxial loading and shear loading. Criteria Survey airlines to determine frequency of impacts that can damage composite structures. Determine effects of applying limit load cycles to fatigue test article. Perfore probability analysis to rela*s factor of safety to level of impact energy. Determine if criteria should result in strengths that are very sensitive to changes in level of energy or damage. Determine effects of oblique impacts. Determine how to account for impacter shape. Dr. William 53. Avery (206) 773-5365 Boeing Defense & Space Croup (206) 477-2489 fax P.O. Box 3999, M/S 82-32 Seattle, WA $8124-2499 Mr. Charles ?. Blankenship (804) 864 -6005 M.S. 118 NASA Langley Research Center Hampton, VA 23665-5225 Dr. Victor L. Chen (213) 496-7415 Dept. 1XX, M/C 18-98 (213) 982-0815 fax Douglas Aircraft Co. 3855 Lakewood Blvd. Long Beach, CA 90846 Mr. H. Benson Dexter (804) M.S. 186B WASA Langley Research Center Hampton, VA 23665-5225 Mr. Ernest F. Dost (206) 393-9632 Boeing Commercial Airplane Co. (206) 477-2489 fax Advanced Programs Composite Group P.O. Box 3707, M.S. 3T-AU Seattle, WA 98124-2499 Mr. Marvin B. Dow (804) M.S. 1883 NASA Langley Research Center Hampton, VA 23665-5225 Dr. Wolf Elber (804) 864-3956 M.S. 266 NASA Langley Research Center Hampton, VA 23665-5225 Gerry Flanagan (516) 346-6510 Grumman Aerospace Corp. (516) 575-7428 fax MS 844-35 Bethpage, WY 11714 Mr. Tim Gillette (818) 847-7913 Lockheed Aeronautical Systems Co. (818) 847-2482 fax Dept. 76-41 Bldg. 369 P.O. Box 551 Burbank, CA 91520 Dr. Michael Craves (617) 253-3628 Massachusetts Institute of Technology -24665 Department of Aeronautics and Astronautics Technical Laboratory for Advanced Composites 77 Massachusetts Avenue, Ra 33-313 Cambridge, MA 02139 Dr. Longin Greszczuk (714) 896-3810 McDonnell Douglas Space Systems A03/365/13-3 5301 Bolsa Ave. Huntington Beach, CA 92647 Mr. C. F. Griffin (818) 847-7913 Lockheed Aeronautical Systems Co. (818) 847-2482 fax Dept. 76-41 Bldg. 369 P.O. Box 551 Burbank, CA 91520 Dr. Christian K. Gunther (215) 499-9526 Boeing Defense & Space Group, Helicopters MS P30-30 P.O. Box 16858 Philadelphia, PA 19142-0858 Mr. Ray E. Horton (206) 477-2243 Boeing Commercial Airplane Co. High Speed Commercial Transport P.O. Box 3707, M.S. 3T-CH Seattle, WA 98124-2499 Dr. Jerrold M. Housner (804) 864-4323 M.S. 240 NASA Langley Research Center Hampton, VA 23665-5225 Dr. Larry B. Llcewicz (206) 393-9630 Boeing Commercial Airplane Co. (206) 477-2689 fax Advanced Programs Composite Group P.O. Box 3707, M.S. 3T-AU Seattle, WA 98124-2499 Dr. Karen E. Jackson (804) 864-4147 M.S. 495 NASA Langley Research Center Hampton, VA 23665-5225 Mr. Wade C. Jackson (804) 864-3468 M.S. 18686 NASA Langley Research Center Hampton, VA 23665-5225 vil Dr. W. Steven Johnson (804) 864-3463 M.S. 1882 RASA Langley Reseerch Center Hampton, VA 23665-5225 Mr. Han-Pin Kan (213) 332-5285 Northrop 1 Northrop Ave. Code 3853/MF Havthorne, CA 90504 Dr. Paul Lagace (617) 253-3628 Massachusetts Institute of Technology ~2465 Department of Aeronautics and Astronautics Technical Laboratory for Advanced Composites 77 Massachusetts Avenue, Ra 33-303 Cambridge, MA 02139 Dr. K. ¥. Lin (206) 543-6334 University of Washington Guggenheia# Hall, FS-10 Seattle, WA 98195 Dr. Jack Lincoln (513) 255-6879 ASD/ENFS Wright Patterson Air Force Base, OH 45433 Mr. Ozzie Lopez (804) 864-3181 M.S. 240 NASA Langley Research Center Hampton, VA 23665-5225 Mr. Carl B. Madsen (801) 251-6634 Hercules Incorporated (801) 251-6676 fax Aerospace Products Croup Bacchus Works, MS N2EA16 Magna, UT 84044-0098 Dr. John E. Masters (804) 864-3460 M.S. 188E NASA Langley Research Center Hampton, VA 23665-5225 Dr. Kevin O*’ Brien (804) 864-3465 M.S. 1888 NASA Langley Research Center Hampton, VA 23665-5225 Mr. C. C. Poe, Jr. (804) 864-3467 M.S. 1888 NASA Langley Research Center Hampton, VA 23665-5225 | vill 4 . (804) 864-3476 . 188 MASA Langley Research Center Hampton, VA 23665-5225 (206) 655-6676 P.O. Box 3707 Seattle, WA 98124-2207 (804) 864-3456 (804) 86-43 18 2 Research Center Hampton, VA 23665-5225 Mr. Charles R&R. Saff (314) McDonnell Aircraft Co. Mail Code 102 1322 P.O. Box 516 St. Lowlis, MO 63166 (818) 847-9413 Lockheed Aeronautical Systems Co. DL76-41/369/8-6 2777 Onterio Ave. Burbank, CA 91520 Dr. Peter Sjoblos (313) 229-3812 University of Dayton Research Institute (513) 229-3433 fax 300 College Park Ave. Dayton, OH 45469-0180 Mr. Joseph Soderquist (202) 267-9585 FAA, AIR-103 800 Independence Ave. SV Vashington, DC 20591 Dr. George &. Springer (415) 723-4135 Professor and Chairman (415) 723-0062 Department of Aeronautics and Astronautics Stanford University Stanford, CA 94305 Dr. Krishna Srinivasan (804) 864 -4266 N.S. 226 NASA Langley Research Center Hampton, VA 23665-5225 Mr. Jim Suarez (316) 575-6552 Grumman Aerospace Corp. (316) 575-7428 fax MS 544-35 Bethpage, WY 11714 Dr. John T. Vang (804) 864-8185 M.S. 240 RASA Langley Research Center Hampton, VA 23665-5225