{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,12]],"date-time":"2026-10-12T19:14:41Z","timestamp":1791832481646,"version":"4.3.4"},"reference-count":32,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2022,8,12]],"date-time":"2022-08-12T00:00:00Z","timestamp":1660262400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>This paper presents an experimental investigation on the mechanisms of damage onset and evolution in unidirectional PEEK\/AS4 carbon fibre reinforced thermoplastic (CFRTP) composites subjected to off-axis compressive loadings. A test fixture was designed to prevent buckling, splitting, and end collapsing of the specimens during the test. A series of compression tests were conducted with specimens of various off-axis angles. The displacement and strain fields of all specimens during the tests were evaluated by the digital image correlation (DIC) method. In combination with the DIC results, the influence of the off-axis angles on the failure mechanisms and nonlinear stress\u2013strain responses were analysed. The corresponding failure mechanisms were examined by scanning electron microscopy (SEM). The fracture angles of the tested specimens were evaluated and analysed according to Puck\u2019s theory. The off-axis compression failure envelope based on LaRC05 and Hashin criteria was presented and compared to the experimental results. It was shown that the LaRC05 criterion can provide accurate predictions when the off-axis angle is larger than 15\u00b0. The complex failure mechanisms were analysed to better understand the effect of ductility of the thermoplastic matrix to the composites. The series of tests provide an experimental failure envelope in combined stress states and can be used for the evaluation of failure theories and the criteria of thermoplastic composites.<\/jats:p>","DOI":"10.3390\/ma15165547","type":"journal-article","created":{"date-parts":[[2022,8,15]],"date-time":"2022-08-15T03:33:20Z","timestamp":1660534400000},"page":"5547","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Off-Axis Compressive Behaviour of Fibre Reinforced Thermoplastic Composites"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5885-8312","authenticated-orcid":false,"given":"Yifan","family":"Ma","sequence":"first","affiliation":[{"name":"Department of Aeronautical Structural Engineering, School of Aeronautics, Northwestern Polytechnical University, Xi\u2019an 710072, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yazhi","family":"Li","sequence":"additional","affiliation":[{"name":"Department of Aeronautical Structural Engineering, School of Aeronautics, Northwestern Polytechnical University, Xi\u2019an 710072, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lu","family":"Liu","sequence":"additional","affiliation":[{"name":"Department of Aeronautical Structural Engineering, School of Aeronautics, Northwestern Polytechnical University, Xi\u2019an 710072, China"},{"name":"Department of Aircraft Design, School of Aircraft, Xi\u2019an Aeronautical Institute, Xi\u2019an 710077, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,8,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2706","DOI":"10.1177\/002199839202601804","article-title":"Compression failure mechanisms in unidirectional composites","volume":"26","author":"Jelf","year":"1992","journal-title":"J. Compos. Mater."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"948","DOI":"10.1016\/j.compscitech.2009.02.010","article-title":"A micromechanical model for kink-band formation: Part I\u2014Experimental study and numerical modelling","volume":"69","author":"Pimenta","year":"2009","journal-title":"Compos. Sci. Technol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"557","DOI":"10.1016\/S0020-7683(98)00029-8","article-title":"On the axial propagation of kink bands in fiber composites: Part i Experiments","volume":"36","author":"Vogler","year":"1999","journal-title":"Int. J. Solids Struct."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"184","DOI":"10.1016\/j.compstruct.2016.01.058","article-title":"On the role of kinking in the bearing failure of composite laminates","volume":"141","author":"Sola","year":"2016","journal-title":"Compos. Struct."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1016\/j.compstruct.2014.11.043","article-title":"Initiation of failure at notches in unidirectional fiber composites","volume":"122","author":"Wind","year":"2015","journal-title":"Compos. Struct."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"183","DOI":"10.1016\/0022-5096(93)90068-Q","article-title":"Compressive failure of fibre composites","volume":"41","author":"Budiansky","year":"1993","journal-title":"J. Mech. Phys. Solids"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"275","DOI":"10.1023\/A:1018779307931","article-title":"Compressive response and failure of fiber reinforced unidirectional composites","volume":"100","author":"Lee","year":"1999","journal-title":"Int. J. Fract."},{"key":"ref_8","first-page":"1","article-title":"In Situ observation of kink-band formation in a unidirectional carbon fiber reinforced plastic by X-ray computed tomography imaging","volume":"25","author":"Ueda","year":"2014","journal-title":"Adv. Compos. Mater."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1016\/j.compositesa.2005.04.016","article-title":"Physically-based failure models and criteria for laminated fibre-reinforced composites with emphasis on fibre kinking: Part I: Development","volume":"37","author":"Pinho","year":"2006","journal-title":"Compos. Part A Appl. Sci. Manuf."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2523","DOI":"10.1007\/BF00550757","article-title":"Compression strength of carbon, glass and kevlar-49 fibre reinforced polyester resins","volume":"15","author":"Piggott","year":"1980","journal-title":"J. Mater. Sci."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"437","DOI":"10.1115\/1.1311276","article-title":"An energy-based model of longitudinal splitting in unidirectional fiber-reinforced composites","volume":"67","author":"Oguni","year":"2000","journal-title":"J. Appl. Mech."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"85","DOI":"10.1016\/j.compstruct.2012.11.005","article-title":"Interaction between kinking and splitting in the compressive failure of unidirectional fiber reinforced laminated composites","volume":"98","author":"Prabhakar","year":"2013","journal-title":"Compos. Struct."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1139","DOI":"10.1016\/S0020-7683(02)00649-2","article-title":"A failure criterion for fiber reinforced polymer composites under combined compression\u2013torsion loading","volume":"40","author":"Yerramalli","year":"2003","journal-title":"Int. J. Solids Struct."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1765","DOI":"10.1016\/S0020-7683(98)00323-0","article-title":"Composite failure under combined compression and shear","volume":"37","author":"Vogler","year":"2000","journal-title":"Int. J. Solids Struct."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1941","DOI":"10.1016\/j.compscitech.2005.01.013","article-title":"Strain rate effect on in-plane shear strength of unidirectional polymeric composites","volume":"65","author":"Tsai","year":"2005","journal-title":"Compos. Sci. Technol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"371","DOI":"10.1016\/S0266-3538(01)00202-0","article-title":"Guidelines for the determination of the parameters in puck\u2019s action plane strength criterion","volume":"62","author":"Puck","year":"2002","journal-title":"Compos. Sci. Technol."},{"key":"ref_17","first-page":"20","article-title":"Specimen size effect in off-axis compression tests of fiber composites","volume":"39","author":"Bing","year":"2008","journal-title":"Mar. Compos. Sandw. Struct."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"119","DOI":"10.1016\/j.compositesb.2013.06.007","article-title":"Compressive damage mechanism of GFRP composites under off-axis loading: Experimental and numerical investigations","volume":"55","author":"Zhou","year":"2013","journal-title":"Compos. Part B Eng."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"2795","DOI":"10.1016\/j.compscitech.2007.02.001","article-title":"Mechanical behavior of unidirectional fiber-reinforced polymers under transverse compression: Microscopic mechanisms and modeling","volume":"67","author":"LLorca","year":"2007","journal-title":"Compos. Sci. Technol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"117","DOI":"10.1016\/j.compositesa.2016.11.018","article-title":"Compressive failure mechanism and strength of unidirectional thermoplastic composites based on modified kink band model","volume":"93","author":"Matsuo","year":"2017","journal-title":"Compos. Part A Appl. Sci. Manuf."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"213","DOI":"10.1016\/j.compositesa.2019.03.034","article-title":"A study on the longitudinal compression strength of fibre reinforced composites under uniaxial and off-axis loads using cross-ply laminate specimens","volume":"121","author":"Thomson","year":"2019","journal-title":"Compos. Part A Appl. Sci. Manuf."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"2015","DOI":"10.1016\/j.compscitech.2006.12.001","article-title":"A Study on the compressive strength of thick carbon fibre\u2013epoxy laminates","volume":"67","author":"Lee","year":"2007","journal-title":"Compos. Sci. Technol."},{"key":"ref_23","first-page":"3","article-title":"Hidden components of DIC: Calibration and shape function\u2014Part 1","volume":"36","author":"Reu","year":"2012","journal-title":"Exp. Tech."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"111891","DOI":"10.1016\/j.compstruct.2020.111891","article-title":"On-axis and off-axis compressive behavior of pultruded GFRP Composites at elevated temperatures","volume":"236","author":"Zhang","year":"2020","journal-title":"Compos. Struct."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Greenhalgh, E.S. (2009). Introduction to failure analysis and fractography of polymer composites. Failure Analysis and Fractography of Polymer Composites, Woodhead Publishing.","DOI":"10.1201\/9781439847510"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"246","DOI":"10.1016\/j.compositesb.2017.09.057","article-title":"Mode I fracture toughness and fractographic investigation of carbon fibre composites with liquid methylmethacrylate thermoplastic matrix","volume":"134","author":"Bhudolia","year":"2018","journal-title":"Compos. Part B Eng."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"107082","DOI":"10.1016\/j.compositesb.2019.107082","article-title":"Analysis of fracture toughness in mode II and fractographic study of composites based on Elium\u00ae 150 thermoplastic matrix","volume":"175","author":"Barbosa","year":"2019","journal-title":"Compos. Part B Eng."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"918","DOI":"10.1177\/002199839002400902","article-title":"The effects of geometry, rate and temperature on the mode I, mode II and mixed-mode I\/II interlaminar fracture of carbon-fibre\/poly(ether-ether ketone) composites","volume":"24","author":"Hashemi","year":"1990","journal-title":"J. Compos. Mater."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Greenhalgh, E.S. (2009). 4-delamination-dominated failures in polymer composites. Failure Analysis and Fractography of Polymer Composites, Woodhead Publishing.","DOI":"10.1533\/9781845696818"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1045","DOI":"10.1016\/S0266-3538(96)00140-6","article-title":"Failure analysis of FRP laminates by means of physically based phenomenological models","volume":"58","author":"Puck","year":"1998","journal-title":"Compos. Sci. Technol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"329","DOI":"10.1115\/1.3153664","article-title":"Failure criteria for unidirectional fiber composites","volume":"47","author":"Hashin","year":"1980","journal-title":"J. Appl. Mech."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"2313","DOI":"10.1177\/0021998312454478","article-title":"Material and structural response of polymer-matrix fibre-reinforced composites","volume":"46","author":"Pinho","year":"2012","journal-title":"J. Compos. Mater."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/15\/16\/5547\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T00:07:49Z","timestamp":1760141269000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/15\/16\/5547"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,8,12]]},"references-count":32,"journal-issue":{"issue":"16","published-online":{"date-parts":[[2022,8]]}},"alternative-id":["ma15165547"],"URL":"https:\/\/doi.org\/10.3390\/ma15165547","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,8,12]]}}}