Nondestructive Computed Tomography Volumetric Void Acceptance Criteria for Heavy Polymer Sections
Computed tomography volumetric void acceptance requires zoning heavy polymer walls by stress field, setting pore limits below 0.1% in tensile skins.
Multi-Scale CT Scanning
Meaning
Sequential computed tomography inspection protocols combining low-resolution full-part scans with targeted high-resolution sub-volume scans capture both global part dimensions and local micro-structural details. Execution of multi-scale CT scanning delivers complete dimensional verification across large polymer housings alongside high-magnification sub-voxel inspection of critical regions. The method governs macro-level warp measurement, micro-void sizing, and localized fiber orientation analysis within a unified coordinate system.
Its scope stops at multi-resolution X-ray computed tomography, leaving optical surface scanning and single-energy planar radiography outside its process boundary.
Hierarchical Acquisition
Multi-resolution volumetric imaging techniques link global part macro-geometry to localized micro-structural defect distribution within polymer matrices. Utilizing multi-scale CT scanning provides comprehensive quality data without forcing full-part scans at impossibly high voxel resolutions.
Resolution Boundary
Capturing sub-micrometre defects across a large automotive structural component in a single scan requires detector sizes and scan durations that are commercially unfeasible. Applying multi-scale CT scanning solves this trade-off by first mapping the full assembly at coarse resolution to detect warp and macro-voids, then zooming into high-stress ribs for high-resolution sub-volume acquisition. Aligning coordinate systems between coarse and fine scan sets demands precise rotation stages and stable thermal environments.
Scan artifacts from surrounding material in sub-volume acquisitions require physical masking or advanced region-of-interest reconstruction algorithms.
Data Fusion
Disconnects between full-part dimensional audits and micro-structural void assessments lead to incomplete structural integrity evaluations. Incorporating multi-scale CT scanning bridges macro-metrology and micro-defect analysis to support accurate FEA strength predictions.