Compaction, strain, and stress anisotropy in porous rocks

Abstract This paper discusses the application of two different techniques for failure analysis of Cu through-silicon vias (TSVs), used in 3D stacked-IC technology. The first technique is GHz Scanning Acoustic Microscopy (GHz- SAM), which not only allows detection of defects like voids, cracks and delamination, but also the visualization of Rayleigh waves. GHz-SAM can provide information on voids, delamination and possibly stress near the TSVs. The second is a reflection-based photoelastic technique (SIREX), which is shown to be very sensitive to stress anisotropy in the Si near TSVs and as such also to any defect affecting this stress, such as delamination and large voids.

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Effects of Structural and Stress Anisotropy on Velocity of Low-Amplitude Compression Waves Propagating Along Principal Stress Directions in Dry Sand.

10.21236/ada151059 ◽

1984 ◽

Author(s):

S. H. H. Lee ◽

H. Y. F. Chu ◽

K. H. Stokoe ◽

Keyword(s):

Principal Stress ◽

Compression Waves ◽

Stress Anisotropy ◽

Stress Directions ◽

Amplitude Compression ◽

Dry Sand ◽

Low Amplitude

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Use of Image Correlation to Measure Macroscopic Strains by Hygric Swelling in Sandstone Rocks

Applied Sciences ◽

10.3390/app11062495 ◽

2021 ◽

Vol 11 (6) ◽

pp. 2495

Author(s):

Belén Ferrer ◽

María-Baralida Tomás ◽

David Mas

Keyword(s):

Cross Correlation ◽

Pore Space ◽

Digital Camera ◽

Experimental Methods ◽

Image Correlation ◽

Rock Surface ◽

Experimental Setup ◽

Porous Rocks ◽

Porous Sandstone ◽

Variable Displacement

Some materials undergo hygric expansion when soaked. In porous rocks, this effect is enhanced by the pore space, because it allows water to reach every part of its volume and to hydrate most swelling parts. In the vicinity, this enlargement has negative structural consequences as adjacent elements support some compressions or displacements. In this work, we propose a normalized cross-correlation between rock surface texture images to determine the hygric expansion of such materials. We used small porous sandstone samples (11 × 11 × 30 mm3) to measure hygric swelling. The experimental setup comprised an industrial digital camera and a telecentric objective. We took one image every 5 min for 3 h to characterize the whole swelling process. An error analysis of both the mathematical and experimental methods was performed. The results showed that the proposed methodology provided, despite some limitations, reliable hygric swelling information by a non-contact methodology with an accuracy of 1 micron and permitted the deformation in both the vertical and horizontal directions to be explored, which is an advantage over traditional linear variable displacement transformers.

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