A micro-CT-based pre-examination workflow for the forensic analysis of automotive brake hose damage

Tool-induced damage to automotive brake hoses presents challenges in forensic examination because tool-induced damage and fatigue-related failure may exhibit similar external appearances. This study proposes a micro-computed tomography (micro-CT)-based pre-examination workflow for forensic brake hose analysis. The proposed approach integrates non-destructive imaging prior to destructive examination to support damage localization, sectioning planning, and preservation of critical evidence. Fatigue-damaged and tool-induced brake hose specimens were analyzed using micro-CT at an 11 μm resolution. Three-dimensional reconstructions and cross-sectional analyses were performed to identify morphological differences between damage types. In addition, a proof-of-concept angle-based quantitative descriptor derived from the circumferential distribution and relative angular arrangement of rupture-related responses was introduced to illustrate the potential of feature-based quantitative analysis within this framework. Micro-CT analysis localized damage sites and identified morphological features in all specimens prior to conventional destructive examination. Fatigue-damaged brake hoses exhibited non-aligned damage locations between outer and inner rubber layers, intact fiber-braiding layers, and interlayer delamination. In contrast, tool-induced damage samples showed continuous cutting paths from exterior to interior layers following the tool insertion direction, with characteristic striation marks and linear fiber cutting. The proposed quantitative descriptor captured different peak configurations among two representative awl-induced specimens and a fatigue-damaged specimen. The proposed workflow demonstrates the potential utility of micro-CT as a non-destructive pre-examination tool for forensic brake hose analysis. This approach may assist conventional forensic examinations by improving evidence preservation and supporting morphological interpretation.