{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,10]],"date-time":"2026-02-10T17:18:55Z","timestamp":1770743935263,"version":"3.49.0"},"reference-count":26,"publisher":"SAGE Publications","issue":"5","license":[{"start":{"date-parts":[[2009,1,29]],"date-time":"2009-01-29T00:00:00Z","timestamp":1233187200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Journal of Composite Materials"],"published-print":{"date-parts":[[2009,3]]},"abstract":"<jats:p> Variable-stiffness laminates that have fiber orientation variation across its planform can be manufactured using advanced fiber placement technology. For such laminates, successive passes of the fiber placement head often overlap resulting in thickness build-up. If a constant thickness is desired, tows will be cut at the course boundary, which can result in small triangular resin-rich areas without any fibers. In this article a theoretical, numerical investigation of the influence of these tow-drop areas on the strength and stiffness of variable-stiffness laminates is performed. The effects of tow width, laminate thickness and staggering in combination with tow-drop areas are studied by making use of finite element simulations. A method for the localization of tow-drop areas is presented, and the expressions for implementing the tow-drop areas in a finite element model are given. Subsequently, progressive failure analyses using the LaRC failure criteria are performed. Failure occurs at tow-drop locations in both the surface plies and underlying plies. Wider tows result in lower strength. No correlation seems to exist between thickness and laminate strength, while staggering has a positive influence on strength. <\/jats:p>","DOI":"10.1177\/0021998308097675","type":"journal-article","created":{"date-parts":[[2009,1,30]],"date-time":"2009-01-30T01:25:07Z","timestamp":1233278707000},"page":"403-425","source":"Crossref","is-referenced-by-count":115,"title":["A Theoretical Model to Study the Influence of Tow-drop Areas on the Stiffness and Strength of Variable-stiffness Laminates"],"prefix":"10.1177","volume":"43","author":[{"given":"Adriana W.","family":"Blom","sequence":"first","affiliation":[{"name":"Delft University of Technology, Department of Aerospace Engineering Kluyverweg 1, 2629 HS, Delft, The Netherlands,"}]},{"given":"Claudio S.","family":"Lopes","sequence":"additional","affiliation":[{"name":"Delft University of Technology, Department of Aerospace Engineering Kluyverweg 1, 2629 HS, Delft, The Netherlands, DEMEGI, Faculdade de Engenharia, Universidade do Porto, R. Dr. Roberto Frias, 4200-465 Porto, Portugal"}]},{"given":"Peter J.","family":"Kromwijk","sequence":"additional","affiliation":[{"name":"Delft University of Technology, Department of Aerospace Engineering Kluyverweg 1, 2629 HS, Delft, The Netherlands"}]},{"given":"Zafer","family":"Gurdal","sequence":"additional","affiliation":[{"name":"Delft University of Technology, Department of Aerospace Engineering Kluyverweg 1, 2629 HS, Delft, The Netherlands"}]},{"given":"P.P.","family":"Camanho","sequence":"additional","affiliation":[{"name":"DEMEGI, Faculdade de Engenharia, Universidade do Porto, R. Dr. Roberto Frias, 4200-465 Porto, Portugal"}]}],"member":"179","published-online":{"date-parts":[[2009,1,29]]},"reference":[{"key":"atypb1","volume-title":"Proceedings of the 16th International Conference on Composite Materials","author":"Roeseler, W.G."},{"key":"atypb2","volume-title":"Design and Manufacture of Elastically Tailored Tow Placed Plates Technical report, NASA\/CR-2002-211919","author":"Tatting, B.F.","year":"2002"},{"key":"atypb3","volume-title":"Automated Finite Element Analysis of Elastically-Tailored Plates Technical report, NASA\/CR-2003-212679","author":"Tatting, B.F.","year":"2003"},{"key":"atypb4","volume-title":"Proceedings of the 46th AIAA\/ASME\/AHS\/ASC Structures, Structural Dynamics and Materials (SDM) Conference","author":"Gurdal, Z."},{"key":"atypb5","volume-title":"Proceedings of the 44th AIAA\/ASME\/ASCE\/AHS\/ASC Structures, Structural Dynamics and Materials (SDM) Conference","author":"Jegley, D.C."},{"key":"atypb6","volume-title":"Proceedings of the 42nd AIAA\/ASME\/AHS\/ASC Structures, Structural Dynamics and Materials Conference","author":"Wu, K.C."},{"key":"atypb7","volume-title":"Proceedings of the 43rd AIAA\/ASME\/AHS\/ASC Structures, Structural Dynamics and Materials Conference","author":"Wu, K.C."},{"key":"atypb8","doi-asserted-by":"publisher","DOI":"10.1016\/j.compstruc.2007.04.016"},{"key":"atypb9","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijsolstr.2007.06.029"},{"key":"atypb10","author":"Blom, A.W.","year":"2006","journal-title":"Journal of Composites: Part B"},{"key":"atypb11","doi-asserted-by":"publisher","DOI":"10.1016\/j.compstruc.2007.04.020"},{"key":"atypb12","volume-title":"Proceedings of the 16th International Conference on Composite Materials","author":"Blom, A.W."},{"key":"atypb13","volume-title":"ABAQUS Version 6.6 User's Manual","author":"ABAQUS, Inc.","year":"2005"},{"key":"atypb14","doi-asserted-by":"publisher","DOI":"10.1016\/j.mechmat.2007.03.005"},{"key":"atypb15","doi-asserted-by":"publisher","DOI":"10.1016\/j.mechmat.2007.03.006"},{"key":"atypb16","volume-title":"Failure Criteria for FRP Laminates in Plane Stress Technical report","author":"D\u00e1vila, C.","year":"2003"},{"key":"atypb17","volume-title":"Failure Models and Criteria for FRP Under In-Plane or Three-Dimensional Stress States Including Shear Non-linearityTechnical report","author":"Pinho, S.","year":"2005"},{"key":"atypb18","doi-asserted-by":"publisher","DOI":"10.1061\/(ASCE)0733-9399(2002)128:11(1119)"},{"key":"atypb19","volume-title":"Standard Test Method for Tensile Properties of Polymer Matrix Composite materials Technical Report","year":"2000"},{"key":"atypb20","volume-title":"Standard Test Method for Compressive Properties of Unidirectional or Crossply Fiber-resin Composites Technical Report","year":"1987"},{"key":"atypb21","volume-title":"Standard Test Method for In-plane Shear Response of Polymer Matrix Composite Materials by test of a \u00b145\u00b0 Laminate Technical Report","year":"1994"},{"key":"atypb22","volume-title":"Standard Test Methods for Mode I Interlaminar Fracture Toughness of Unidirectional Fiber-reinforced Polymer Matrix Composites Technical Report","year":"2001"},{"key":"atypb23","doi-asserted-by":"publisher","DOI":"10.1016\/j.compscitech.2005.12.023"},{"key":"atypb24","volume-title":"Proceedings of the 4th European Conference on Composites: Testing and Standardisation","author":"Martin, R."},{"issue":"2","key":"atypb25","doi-asserted-by":"crossref","first-page":"165","DOI":"10.1016\/j.compositesa.2005.04.023","volume":"37","author":"Camanho, P.","year":"2006","journal-title":"Composites Part A: Applied Science and Manufacturing"},{"key":"atypb26","doi-asserted-by":"publisher","DOI":"10.1016\/j.compscitech.2007.02.005"}],"container-title":["Journal of Composite Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/0021998308097675","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/0021998308097675","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,3,3]],"date-time":"2025-03-03T12:56:23Z","timestamp":1741006583000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.sagepub.com\/doi\/10.1177\/0021998308097675"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2009,1,29]]},"references-count":26,"journal-issue":{"issue":"5","published-print":{"date-parts":[[2009,3]]}},"alternative-id":["10.1177\/0021998308097675"],"URL":"https:\/\/doi.org\/10.1177\/0021998308097675","relation":{},"ISSN":["0021-9983","1530-793X"],"issn-type":[{"value":"0021-9983","type":"print"},{"value":"1530-793X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2009,1,29]]}}}