SpaceNDT (FFG - ASAP 14)
Background
This work was carried out within the framework of the Austrian Research Promotion Agency's (FFG) ASAP program and was funded by the Austrian Federal Government.
The SpaceNDT project combines advanced non-destructive testing (NDT) technologies, such as micro-computed tomography (XCT), phase-contrast X-ray imaging (DPC), active thermography (IRT), and digital shearography (DS), to investigate the material behavior of advanced materials used in aerospace applications during thermo-mechanical stress testing. The main objectives of the consortium leader, FH OÖ Forschungs & Entwicklungs GmbH, and the consortium partners, Aerospace & Advanced Composites GmbH, Peak Technology GmbH, and FOTEC Forschungs- und Technologietransfer GmbH, are to create defect catalogs for polymer matrix composites (PMC), multi-material, and additively manufactured (AM) parts, and to predict the influence of defects on fatigue life using FEA simulations.
``` One of the main challenges to accelerating the acceptance and use of advanced materials (e.g., PMCs and AM parts) at ESA is establishing a widely accepted quality system for materials and processes, including appropriate NDT methods. During SpaceNDT, we are employing advanced NDT technologies to overcome the limitations of standard methods in detecting microcracks, delamination, debonding, and fracture propagation on reference objects and real PMC, multi-material, and AM aerospace components. Ultimately, this project (spaceXCT, Project: 854042) pursues efforts to develop NDT-based "Best Practice Analysis Guidelines" to strengthen Austria's role as a competent partner in the space sector with regard to advanced manufacturing and NDT.
According to the ESA and NASA roadmap regarding materials, structures, and manufacturing processes, reliability and weight reduction are two key themes for future developments in the space sector. In general, lightweight polymer matrix composites (PMCs) and metallic structures are essential for producing the most efficient, optimized, and application-specific components, especially when exposed to extreme environmental conditions. While most materials used in spacecraft are similar to those used in terrestrial applications, the operating environment is vastly different. The physical and chemical environment in low Earth orbit (LEO) and geosynchronous orbit (GEO) exposes structural materials to highly aggressive oxidation and radiation, ultimately leading to degradation. Several factors exert significant forces on lightweight and multifunctional materials and structures, most notably:
- high-energy particles and ionizing radiation from the Sun,
- steep thermal waves and gradients in the upper atmosphere,
- high-speed meteoroids and debris particles, and
- high temperatures encountered by reentry vehicles for planetary missions, which can exceed 1,600°C.
The harsh vacuum in the thermosphere leads to outgassing of materials, which can result in discharges or arcing. Ambient vacuum and extreme temperatures can cause shrinkage of parts, embrittlement at low temperatures, microcracks, and fatigue damage due to temperature cycling.
Objectives
- The first main objective is the qualitative and quantitative characterization of defects, e.g., cracks and microcracks in the (sub-)micrometer range, in samples and components made of polymer matrix composites.
- The second main objective is to extend experience with in-situ NDT of polymer matrix composite components to space components made of polymer matrix composites and metal hybrids, e.g., landing gear and a mounting device.
- The third main objective is the qualitative and quantitative characterization of the material properties of additively manufactured parts, e.g., the behavior of gas bubbles and cracks with respect to heat treatment.