TY - JOUR
T1 - To measure is to know
T2 - Evaluating indirect measurement techniques for observing the damage tolerance behaviour of spot welded thermoplastic composites
AU - Smeets, Eva T.B.
AU - Rans, Calvin D.
AU - Castro, Saullo G.P.
AU - Villegas, Irene F.
PY - 2023
Y1 - 2023
N2 - In thermoplastic composite joints with a circular ultrasonic spot weld, the damage growth is located at the interface between the joined components. This means that any damage in these joints is invisible from the outside. This experimental study compares three different in-situ methods to measure the damage growth indirectly. The motivation lies in the potential benefits of using multi-spot welded joints for increased damage tolerance and the need to prove the damage arresting and damage progression behaviour for certification. The current study focused on measuring the damage in single-spot welded Single Lap Shear (SLS) joints during fatigue test with the global specimen compliance, the local out-of-plane displacement and the local strain on the surface. Digital Image Correlation (DIC) measurements were used to obtain the local quantities. The results showed that the local quantities are better suited to obtain detailed information on the damage state. The local surface strain showed more distinct features that facilitate the recognition of damage locations. The benefits and challenges of all methods are discussed as well as the difference in the level of detail, generalization and the prior knowledge necessary to obtain the damage state.
AB - In thermoplastic composite joints with a circular ultrasonic spot weld, the damage growth is located at the interface between the joined components. This means that any damage in these joints is invisible from the outside. This experimental study compares three different in-situ methods to measure the damage growth indirectly. The motivation lies in the potential benefits of using multi-spot welded joints for increased damage tolerance and the need to prove the damage arresting and damage progression behaviour for certification. The current study focused on measuring the damage in single-spot welded Single Lap Shear (SLS) joints during fatigue test with the global specimen compliance, the local out-of-plane displacement and the local strain on the surface. Digital Image Correlation (DIC) measurements were used to obtain the local quantities. The results showed that the local quantities are better suited to obtain detailed information on the damage state. The local surface strain showed more distinct features that facilitate the recognition of damage locations. The benefits and challenges of all methods are discussed as well as the difference in the level of detail, generalization and the prior knowledge necessary to obtain the damage state.
KW - Damage growth
KW - Digital image correlation (DIC)
KW - Thermoplastic composites
KW - Ultrasonic spot welding
UR - http://www.scopus.com/inward/record.url?scp=85167459814&partnerID=8YFLogxK
U2 - 10.1016/j.jajp.2023.100152
DO - 10.1016/j.jajp.2023.100152
M3 - Article
AN - SCOPUS:85167459814
VL - 8
JO - Journal of Advanced Joining Processes
JF - Journal of Advanced Joining Processes
SN - 2666-3309
M1 - 100152
ER -