3D Printing for Intelligent Metallic Structures

Structural Health Monitoring (SHM) is needed both to improve life-safety and to reduce the direct operational costs. Nowadays, a new concept called effective Structural Health Monitoring (eSHM) has proven to be efficient but still needs to pass different technological readiness levels to enable its implementation. This work demonstrates the feasibility study of eSHM systems produced by 3D printing or additive manufacturing. The objective of this work is to prove that the eSHM system has reached technological readiness level 3 (TRL3) and to indicate that during fatigue the integrated system had no influence on the crack initiation behaviour. First, two different techniques (selective laser melting and laser metal deposition) were used for the production of four-point bending feasibility test specimens with the integrated eSHM system. Next, a four-point bending test was selected, the specimens were subjected to the so-called step test method with constant fatigue stress amplitude and a constant R ratio. The fatigue behaviour of stainless steel and titanium alloy was studied with emphasis on crack initiation and detection. This study proves that the eSHM reaches the TRL3.The investigated system always detected cracks although further investigation is needed since higher TRL are required and the detection capability can be improved.