Transition in the pattern of cracks resulting from memory effects in paste

TL;DR

This study investigates how external vibrations influence crack patterns in drying paste, revealing a transition from perpendicular to parallel cracks as paste concentration decreases, enabling controlled pattern design.

Contribution

It demonstrates a transition in crack orientation linked to paste concentration, highlighting the role of flow-induced memory effects in pattern formation.

Findings

Crack orientation shifts from perpendicular to parallel with decreasing solid volume fraction.

External vibration induces a flow pattern that influences crack morphology.

Controlled crack pattern design is possible through manipulation of initial vibrations.

Abstract

Experiments involving vibrating pastes before drying were performed for the purposes of controlling the crack patterns that appear in the drying process. These experiments revealed a transition in the direction of lamellar cracks from perpendicular to parallel when compared with the direction of the initial external vibration as the solid volume fraction of the paste is decreased. This result suggests a transition in the "memory" in paste, which is visually represented as morphological changes in the crack pattern. Given that the memory in paste represents the flow pattern induced by the initial external vibration, it should then be possible to control and design various crack patterns, such as cellular, lamellar, radial, ring, spiral, and others.