Measurement of manufacture assembly stresses in thick composite components using a modified DHD method

Abstract

Understanding of the through-thickness distribution of assembly stresses caused by manufacture process-induced distortion (PID) in thick composite components is essential for safety and reliability assessment. Inspired by deep-hole drilling (DHD) method which is widely used to reconstruct residual stresses in thick metallic components, current research attempts to extend and modify the DHD technique to measure the manufacture assembly stresses in composite components. It is observed that the modified DHD technique can capture the global deformation profiles induced by the assembly stresses, but the previous DHD stress calculation method produces large stress errors. An integrating stress calculation method is then proposed by combining the homogeneous global and the layer-wise antistrophic stress-strain solutions. It is demonstrated that the assembly stresses calculated by the proposed integrating calculation method are significantly improved and it is feasible to measure the manufacture assembly stresses of thick composite components with the modified DHD technique.

Residual stress in fiber reinforced thermosetting composites: A review of measurement techniques

“…However, it was still possible to measure assembly stresses but some significant calculation errors were found. A study from Hu et al [ 29 ] went on to modify the approach taken by Garza et al by implementing an integrating stress calculation method, finding this reduced calculation errors and gave results for assembly stress which matched well with simulations.…”

“…There has been a huge breadth of research that has been undertaken in the numerical modeling of the manufacturing process of fiber reinforced laminates, as Baran et al [3] showed. It is clear that much progress has been made over the past few decades and it is now possible to accurately predict many physical phenomena accurately by choosing and correctly implementing one of the [11,[13][14][15][16] Hole-drilling [19,27] [20] -Potentially global scale if laminate is thin -Bixal stress distribution -Accuracy decreases with depth of cut [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] Ring-core [40][41][42] Note: ?, there is potential but it has not been done to date; , it is possible with some caveats. many models and techniques available.…”

Shape distortion in composites: sources, characterization, and remedies

“…The strain changes are measured and processed [98,114]. This method is also used with a combination of speckle interferometry [115][116][117][118], Moire´s interferometry, and holographic interferometry [119][120][121][122].…”