Slice compression test

Fig. 3.13. Schematic drawing of slice compression test on a composite slice containing multiple fibers.

Fig. 3.14. Schematic drawings of slice compression test on a single fiber composite (a) before loading (b) peak loading with a maximum fiber protrusion length, (c) after unloading with a residual fiber protrusion length, After Hsueh (1993),...

Hsueh, C.H. (1993). Analysis of slice compression tests for aligned ceramic matrix composites. Acta Metall. Mater. 41, 3585-3593. 

Lu, G.Y. and Mai, Y.W. (1994). A theoretical model for evaluation of interfacial properties of fiber reinforced ceramics with the slice compression test. Composites Sci. Technol. 51, 565-574. 

The indirect methods for fiber-matrix adhesion-level measurement are shown in Fig. 2. These include the variable curvature method the slice compression test, the ball compression test, the fiber-bundle pull-out test the use of dynamical-mechanical thermal analysis and voltage-contrast X-ray photoelectron spectroscopy (VCXPS). 

The slice compression test has been applied to polymer-matrix composites even though it was developed to probe the interface in ceramic matrix composites [16]. A thin slice sample of unidirectional composite is produced with the cut surface perpendicular to the fiber axis. The surfaces are cut and polished to be parallel to each other and perpendicular to the fibers. The thin slice is loaded in compression in the fiber axis direction with two plates. One of the plates is made of a very hard material such as silicon nitride and the other of a soft material, e.g. pure aluminum which can deform as the fibers are compressed into it. The thickness of the slice must be controlled to allow the fibers to debond without failing in compression as well as allowing them to slide inside through the matrix. The depth of the fiber indentation into the plate can be related to the interfacial shear strength [17]. 

The granite used in the current study was obtained from the Lingyan Mountain, located in Suzhou City, Jiangsu Province, China. The rock was sliced and polished into the cubic specimens with the size of around 50 mm x 50 mm x 50 mm. The uniaxial compression tests for the specimens were employed using the YE-2000 type of hydraulic machine, produced by the Zhejiang Jingyuan Machinery Company Limited, China. The distances from the camera to the specimens were about 5.0 m. The video camera was placed normal to the rock specimen surface in order to eliminate the perspective errors and lens distortion. 

The texture of bread was evaluated based on an instrumental Texture Profile Analysis (TPA). Bread slices (height 30 mm) were compressed with a universal testing machine (Zwick 1445, Ulm, G) to 15 mm with two repeating cycles. The crumb firmness and the elastic recovery were evaluated as described in ref. 8. The modulus of deformability of starch and flour gels was evaluated as described in ref. 7. 

---