Visual Analysis of Defects in Glass Fiber Reinforced Polymers for 4DCT Interrupted In situ Tests

Abstract

Material engineers use interrupted in situ tensile testing to investigate the damage mechanisms in composite materials. For each subsequent scan, the load is incrementally increased until the specimen is completely fractured. During the interrupted in situ testing of glass fiber reinforced polymers (GFRPs) defects of four types are expected to appear: matrix fracture, fiber/matrix debonding, fiber pull-out, and fiber fracture. There is a growing demand for the detection and analysis of these defects among the material engineers. In this paper, we present a novel workflow for the detection, classification, and visual analysis of defects in GFRPs using interrupted in situ tensile tests in combination with X-ray Computed Tomography. The workflow is based on the automatic extraction of defects and fibers. We introduce the automatic Defect Classifier assigning the most suitable type to each defect based on its geometrical features. We present a visual analysis system that integrates four visualization methods: 1) the Defect Viewer highlights defects with visually encoded type in the context of the original CT image, 2) the Defect Density Maps provide an overview of the defect distributions according to type in 2D and 3D, 3) the Final Fracture Surface estimates the material fracture's location and displays it as a 3D surface, 4) the 3D Magic Lens enables interactive exploration by combining detailed visualizations in the region of interest with overview visualizations as context. In collaboration with material engineers, we evaluate our solution and demonstrate its practical applicability.

open_iA: A tool for processing and visual analysis of industrial computed tomography datasets

“…• MObjects (Reh, Gusenbauer, Kastner, Gröller, & Heinzl, 2013) now included in the FeatureScout tool, provides a way to visualize the average shape of a collection of similar objects, such as fibers or pores. • The 4DCT tools (Amirkhanov et al, 2016) • Fuzzy Feature Tracking (Reh, Amirkhanov, Heinzl, Kastner, & Gröller, 2015) provides graphs for tracking the creation, continuation, and merge of defects between different stages of fatigue testing. • GEMSe (Fröhler, Möller, & Heinzl, 2016) supports users in finding optimal parameters for their volume segmentation tasks without requiring a ground truth.…”

Thickness accuracy of virtually designed patient‐specific implants for large neurocranial defects

“…Cranial vault thickness of the complete specimens and each reconstructed cranial implant was computed based on extracted surface data (STL) in open_iA (Fröhler et al, 2019). Thickness values are determined for landmarks that are situated in the implant specific area.…”

STAR: Visual Computing in Materials Science

“…The authors computed stress‐strain curves as well as temperature variation fields of the specimens encoded in 2D colormaps and used 2D scanning electron micropcopy (SEM) micrographs for verification. Also Amirkhanov et al [AAS*16] proposed a visual analysis tool for exploring and analyzing defects and deformations occurring under increasing load conditions in glass fiber reinforced polymers by applying 4DCT interrupted in‐situ tensile tests. The authors employ surface based representations as well as heat maps showing the evolution of defects and deformations over time. Fatigue Testing and Damage Analysis is a further escalation step of the previously discussed area of stress and deformation investigation.…”

“…Patterson et al [PCH*15] visualize and investigate cellular materials under strain with in‐situ X‐ray synchroton tomography to get the mechanical properties of the material, which are important for predicting lifetime performance, damage path‐ways and stress recovery. In order to explore the damage mechanisms in composite materials such as glass fiber reinforced polymers under increasing load Amirkhanov et al [AAS*16] presented a tool for the analysis of 4D‐XCT data. Aside the extraction and classification of the corresponding defects in each step of the insitu test into matrix fractures, fiber/matrix debondings, fiber pull‐outs, and fiber fractures, various exploration techniques are proposed to highlight the defect regions in context of the XCT data.…”