Lock-In Thermography and Ultrasonic Testing of Impacted Basalt Fibers Reinforced Thermoplastic Matrix Composites

Abstract

Basalt fibers are receiving increasing consideration because they seem to be adequate as reinforcement of composites and to comply with the environmental safeguard rules. However, many factors affect the performance of composite material, demanding specific testing; one may be performance assessment under impact tests. The attention of the present work is focused on the detection of impact damage in basalt-based composites with two non-destructive testing techniques: lock-in thermography (LT) and ultrasonic testing (UT). Two different types of materials are considered which both include basalt fibers as reinforcement but two different matrices: Polyamide and polypropylene. Polypropylene is used either pure or modified with the addition of a coupling agent; the latter improves the fiber/matrix interface strength, giving in practice, a material of different characteristics. Specimens are first subjected to low-velocity impact tests and then non-destructively examined with the two above mentioned techniques. The obtained results are analyzed and compared to highlight the advantages and limitations of the two techniques to detect impact damage in basalt-based composites. Both techniques seem effective for the inspection of polyamide/basalt composite; in particular, there is a general agreement between results. Conversely, UT seems not suitable for the inspection of polypropylene/basalt composites because of their superficial porosity, while lock-in thermography is effective also for this type of composite material.

Adaptive spectral band integration in flash thermography: Enhanced defect detectability and quantification in composites

“…This is one of the typical defect types that may occur in composites, in which the defected region extends over several plies in the depth direction. In earlier studies by other researchers, impact damages have been investigated with infrared thermography both while the impact occurs [46,47] and with lock-in thermography after their formation [46][47][48]. This is a particularly demanding inspection case considering the increased lateral heat diffusion in CFRP on the one hand, and the complex nature of BVID on the other hand.…”

Nondestructive Testing in Composite Materials

“…Most of the papers of this special issue involve fiber reinforced composites [7][8][9][10][11][12]. These include different types of matrices and fibers that are used for different applications going from the transport industry (aircraft, trains, ships, etc.)…”

“…Infrared thermography is widely used in the inspection of materials and structures, amongst them composites, thanks to its remote deployment through the use of a non-contact imaging device. Lock-in thermography coupled with ultrasonic phased array was used by Boccardi et al [12] to detect impact damage in basalt-based composites. In particular, two types of materials that include basalt fibers as reinforcement of two matrices were considered: polyamide and polypropylene.…”

Designing the organoplastics based on aromatic polyamide, study of their operational properties and applicability

“…Such PCMs are quite capable of competing with known standard materials (bronze, babbit, cast iron, etc.). However, despite the diversity of OP, their use is constrained by the insufficient adhesion between the polymeric matrix and a filler, as well as the OF agglomeration [16], which leads to the anisotropy of properties and pore formation.…”