{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,29]],"date-time":"2026-07-29T22:21:29Z","timestamp":1785363689574,"version":"3.55.0"},"reference-count":28,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2025,7,6]],"date-time":"2025-07-06T00:00:00Z","timestamp":1751760000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)","award":["DFG-506217074."],"award-info":[{"award-number":["DFG-506217074."]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>Since lightweight design and construction safety is a crucial element in different sectors of industry, the use of SMA wires in composites could improve the monitoring and adjustment of mechanical properties starting from the product development process through to field use. This work shows how embedded SMA wires can lead to a better understanding of applied forces to a composite structure made of GFRP laminates. To achieve this, different methods will be addressed. Besides mechanical testing of the GFRP-samples with embedded SMA wires, NDT-methods like active thermography, high-frequency ultrasonic testing, and computer tomography are used to detect the SMA wires, whereby thermography and computer tomography are best suited. In this study, the location and the amount of the applied force on GFRP composites with embedded SMA wires could be characterized with relative resistance changes. It is shown that SMA wires with a diameter of 250 \u00b5m are preferred to wires with a diameter of 100 \u00b5m due to production process and better performance under load (4N force plateau for 100 \u00b5m in contrast to 25N force plateau for 250 \u00b5m wires). Furthermore, Young\u2019s modulus of the GFRP composites with embedded SMA wires was measured and is similar for various samples with 30.8 GPa on average.<\/jats:p>","DOI":"10.3390\/ma18133193","type":"journal-article","created":{"date-parts":[[2025,7,7]],"date-time":"2025-07-07T04:43:37Z","timestamp":1751863417000},"page":"3193","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Monitoring of Layered Thermoplastic Composites Using Shape Memory Alloys as Integrated Sensors for Multifunctional Lightweight Structures"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5998-4038","authenticated-orcid":false,"given":"Michael","family":"Schwarz","sequence":"first","affiliation":[{"name":"Chair for Lightweight Systems, Saarland University, 66123 Saarbr\u00fccken, Germany"},{"name":"Fraunhofer Institute for Nondestructive Testing IZFP, Campus E3 1, 66123 Saarbr\u00fccken, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marius","family":"Weiler","sequence":"additional","affiliation":[{"name":"Chair for Lightweight Systems, Saarland University, 66123 Saarbr\u00fccken, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1845-3166","authenticated-orcid":false,"given":"Saravanan","family":"Palaniyappan","sequence":"additional","affiliation":[{"name":"Group of Composites and Material Compounds (PVW), Institute of Materials Science and Engineering (IWW), Chemnitz University of Technology, 09125 Chemnitz, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5534-4116","authenticated-orcid":false,"given":"Steven","family":"Quirin","sequence":"additional","affiliation":[{"name":"Chair for Lightweight Systems, Saarland University, 66123 Saarbr\u00fccken, Germany"},{"name":"Fraunhofer Institute for Nondestructive Testing IZFP, Campus E3 1, 66123 Saarbr\u00fccken, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2648-7489","authenticated-orcid":false,"given":"Maik","family":"Trautmann","sequence":"additional","affiliation":[{"name":"Group of Composites and Material Compounds (PVW), Institute of Materials Science and Engineering (IWW), Chemnitz University of Technology, 09125 Chemnitz, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1522-3560","authenticated-orcid":false,"given":"Guntram","family":"Wagner","sequence":"additional","affiliation":[{"name":"Group of Composites and Material Compounds (PVW), Institute of Materials Science and Engineering (IWW), Chemnitz University of Technology, 09125 Chemnitz, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3471-1516","authenticated-orcid":false,"given":"Hans-Georg","family":"Herrmann","sequence":"additional","affiliation":[{"name":"Chair for Lightweight Systems, Saarland University, 66123 Saarbr\u00fccken, Germany"},{"name":"Fraunhofer Institute for Nondestructive Testing IZFP, Campus E3 1, 66123 Saarbr\u00fccken, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,7,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"248","DOI":"10.4028\/www.scientific.net\/AMM.663.248","article-title":"Shape memory alloys in automotive applications","volume":"663","author":"Jani","year":"2014","journal-title":"Appl. Mech. Mater."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"695","DOI":"10.1002\/jbm.820100505","article-title":"Biocompatibility of nitinol alloy as an implant material","volume":"10","author":"Castleman","year":"1976","journal-title":"J. Biomed. Mater. Res."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"687","DOI":"10.1016\/j.cirp.2007.10.001","article-title":"The design and manufacture of biomedical surfaces","volume":"56","author":"Ramsden","year":"2007","journal-title":"CIRP Ann."},{"key":"ref_4","unstructured":"Duerig, T.W., Melton, K.N., and Stockel, D. (2013). Engineering Aspects of Shape Memory Alloys, Butterworth-Heinemann."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2185","DOI":"10.1098\/rspa.1997.0117","article-title":"The selection of mechanical actuators based on performance indices","volume":"453","author":"Huber","year":"1997","journal-title":"Proc. R. Soc. Lond. Ser. A Math. Phys. Eng. Sci."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Straub, T., Fell, J., Zabler, S., Gustmann, T., Korn, H., and Fischer, S.C.L. (2023). Characterization of Filigree Additively Manufactured NiTi Structures Using Micro Tomography and Micromechanical Testing for Metamaterial Material Models. Materials, 16.","DOI":"10.3390\/ma16020676"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1117\/12.514387","article-title":"Integrating shape memory alloys into composite materials: Structural optimization and its implications on lightweight design","volume":"Volume 5062","author":"Boller","year":"2003","journal-title":"Smart Materials, Structures, and Systems"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1016\/j.compositesb.2016.08.033","article-title":"Enhancement of interfacial bonding strength of SMA smart composites by using mechanical indented method","volume":"106","author":"Yuan","year":"2016","journal-title":"Compos. Part B Eng."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Bechtel, S., Meisberger, M., Klein, S., Heib, T., Quirin, S., and Herrmann, H.-G. (2020). Estimation of the Adhesion Interface Performance in Aluminum-PLA Joints by Thermographic Monitoring of the Material Extrusion Process. Materials, 13.","DOI":"10.3390\/ma13153371"},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Palaniyappan, S., Ramesha, H.K., Trautmann, M., Quirin, S., Heib, T., Herrmann, H.-G., and Wagner, G. (2024). Surface Treatment Strategies and Their Impact on the Material Behavior and Interfacial Adhesion Strength of Shape Memory Alloy NiTi Wire Integrated in Glass Fiber-Reinforced Polymer Laminate Structures. Materials, 17.","DOI":"10.3390\/ma17143513"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"284","DOI":"10.1016\/j.compositesb.2018.09.101","article-title":"Structural deformation performance of glass fiber reinforced polymer composite beam actuated by embedded indented SMA wires","volume":"159","author":"Guoqing","year":"2019","journal-title":"Compos. Part B Eng."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"112544","DOI":"10.1016\/j.compstruct.2020.112544","article-title":"Self-sensing-based deflection control of carbon fibre-reinforced polymer (CFRP)-based shape memory alloy hybrid composite beams","volume":"251","year":"2020","journal-title":"Compos. Struct."},{"key":"ref_13","unstructured":"(2004). Standard Specification for Wrought Nickel-Titanium Shape Memory Alloys for Medical Devices and Surgical Implants (Standard No. ASTM F2063-18)."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Meola, C. (2012). Infrared Thermography: Recent Advances and Future Trends, Bentham Science.","DOI":"10.2174\/97816080514341120101"},{"key":"ref_15","unstructured":"M\u00f6llmann, K.P., Karst\u00e4dt, D., Pinno, F., and Vollmer, M. (October, January ). Selected critical applications for thermography: Convections in fluids, selective emitters and highly reflecting materials. Proceedings of the Infrared Camera Calibration Conference, Las Vegas, NV, USA."},{"key":"ref_16","unstructured":"Howell, J.R., Pinar, M.M., and Robert, S. (2010). Thermal Radiation Heat Transfer, Taylor & Francis. [5th ed.]."},{"key":"ref_17","unstructured":"(2010). Zerst\u00f6rungsfreie Pr\u00fcfung\u2014Aktive Thermografie (Standard No. DIN 54192:2010-11)."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1016\/j.compositesb.2013.09.036","article-title":"Characterizing damage in CFRP structures using flash thermography in reflection and transmission configurations","volume":"57","author":"Maierhofer","year":"2014","journal-title":"Compos. Part B Eng."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"91","DOI":"10.1016\/j.infrared.2016.01.019","article-title":"Low-velocity impact damage characterization of carbon fiber reinforced polymer (CFRP) using infrared thermography","volume":"76","author":"Li","year":"2016","journal-title":"Infrared Phys. Technol."},{"key":"ref_20","first-page":"1011","article-title":"Inspections of Helicopter Composite Airframe Structures using Conventional and Emerging Nondestructive Testing Methods","volume":"39","author":"Liew","year":"2011","journal-title":"J. Test. Eval."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"380","DOI":"10.1016\/j.engfailanal.2005.02.007","article-title":"Non-destructive evaluation of aerospace materials with lock-in thermography","volume":"13","author":"Meola","year":"2006","journal-title":"Eng. Fail. Anal."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1007\/s10921-019-0578-5","article-title":"Nondestructive testing of a complex aluminium-CFRP hybrid structure with EMAT and thermography","volume":"38","author":"Schwarz","year":"2019","journal-title":"J. Nondestruct. Eval."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"113","DOI":"10.1016\/j.infrared.2015.02.006","article-title":"Non-destructive testing of composite materials by means of active thermography-based tools","volume":"71","author":"Lizaranzu","year":"2015","journal-title":"Infrared Phys. Technol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"52","DOI":"10.1016\/j.ndteint.2014.04.002","article-title":"Modelling and evaluation of pulsed and pulse phase thermography through application of composite and metallic studies","volume":"66","author":"Waugh","year":"2014","journal-title":"NDTE Int."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"537","DOI":"10.1016\/j.ndteint.2011.05.012","article-title":"Active thermography as a quantitative method for non-destructive evaluation of porous carbon fiber reinforced polymers","volume":"44","author":"Mayr","year":"2011","journal-title":"NDTE Int."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1985","DOI":"10.1007\/s12206-012-0510-8","article-title":"P ThermoPoD: A reliability study on active infrared thermography for the inspection of composite materials","volume":"26","author":"Duan","year":"2012","journal-title":"J. Mech. Sci. Technol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.compositesb.2014.09.018","article-title":"Defect detection in CFRP by infrared thermography with CO2 Laser excitation compared to conventional lock-in infrared thermography","volume":"69","author":"Keo","year":"2015","journal-title":"Compos. Part B Eng."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"113233","DOI":"10.1016\/j.sna.2021.113233","article-title":"Analysis and evaluation of bundled SMA actuator wires","volume":"333","author":"Britz","year":"2022","journal-title":"Sens. Actuators A Phys."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/18\/13\/3193\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T18:05:24Z","timestamp":1760033124000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/18\/13\/3193"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,7,6]]},"references-count":28,"journal-issue":{"issue":"13","published-online":{"date-parts":[[2025,7]]}},"alternative-id":["ma18133193"],"URL":"https:\/\/doi.org\/10.3390\/ma18133193","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,7,6]]}}}