Fiber- and Particle-Reinforced Composite Materials with the Gurtin-murdoch and Steigmann-Ogden Surface Energy Endowed Interfaces

Modern advances in material science and surface chemistry lead to creation of composite materials with enhanced mechanical, thermal, and other properties. It is now widely accepted that the enhancements are achieved due to drastic reduction in sizes of some phases of composite structures. This leads to increase in surface to volume ratios, which makes surface- or interface-related effects to be more significant. For better understanding of these phenomena, the investigators turned their attention to various theories of material surfaces. This paper is a review of two most prominent theories of that kind, the Gurtin-Murdoch and Steigmann-Ogden theories. Here, we provide comprehensive review of relevant literature, summarize the current state of knowledge, and present several new results.

Characterisation of bone regeneration in 3D printed ductile PCL/PEG/hydroxyapatite scaffolds with high ceramic microparticle concentrations

3D printed bioactive glass or bioceramic particle reinforced composite scaffolds for bone tissue engineering currently suffer from low particle concentration (<50 wt%) hence low osteoconductivity. Meanwhile, composites with very high...

A review on filler materials for brazing of carbon-carbon composites

It is needed to join C/C composite to other materials since its individual use is limited. Brazing is a method to join C/C composite that has been studied most, maturest and most widely used in recent decades. The quality of a brazed joint is largely determined by the intermediate layer material. It is significant to choose filler materials reasonably. C/C composite is difficult to be wetted by common brazing filler materials. Moreover, there is a large difference in the coefficient of thermal expansion between C/C composite and metals. At present, there is no brazing filler alloy exclusively recommended for commercial C/C composites and metal brazing. Usually, active elements are added into filler metals to improve the wettability of them on C/C composite surface. The existing research includes Al-based, Ag-based, Cu-based, Ti-based, Ni-based brazing filler metals, and so on. In addition, various particle reinforced composite filler materials and stress buffer metal interlayer added composite filler materials have been studied for brazing C/C composite. The summarization of the overview on the application of intermediate filler metals is made in this paper. The basic reference basis is provided for the subsequent brazing filler metals development and joint performance improvement for C/C composite brazing.

Determination of Local Strain Distribution at the Level of the Constituents of Particle Reinforced Composite: An Experimental and Numerical Study

This paper is devoted to numerical and experimental investigation of the strain field at the level of the constituents of two-phase particle reinforced composite. The research aims to compare the strain distributions obtained experimentally with the results obtained by using a computational model based on the concept of the representative volume element. A digital image correlation method has been used for experimental determination of full-field strain. The numerical investigation was conducted by the finite element analysis of the representative volume element. Moreover, usage of the novel method of assessment of the speckle pattern applicability for the measurement of local fields by using the digital image correlation method has been proposed. In general, the obtained experimental and numerical results are in good agreement although some discrepancies between the results have been noticed and discussed.

An adaptive p-FEM for three-dimensional concrete aggregate models

Numerical simulation for concrete aggregate models (CAMs) with different shape aggregates usually requires high accuracy and convergence near the material interfaces. But high memory usage will be needed for those traditional finite element methods such as the method by using mesh refinement throughout the domain. Thus, an adaptive [Formula: see text]-version finite element method ([Formula: see text]-FEM) is proposed in this paper for the solution of 3D CAM problems, and meanwhile the resulting adaptive computational algorithm and post-processing program are presented. We firstly focused two typical 3D weak discontinuity problems on the influence of different convergence criterions for the computational results of each point on the interface in order to verify the efficiency and convergence of the resulting [Formula: see text]-FEM, and then this method is successfully applied to the numerical simulation of CAMs with different shape aggregates. In addition, an efficient hybrid realization method which combines ANSYS and Hypermesh software is also presented in order to quickly establish the geometric models of 3D CAMs. The numerical results have been shown that the proposed [Formula: see text]-FEM can efficiently solve the concrete-like particle-reinforced composite problems and more accurate numerical results can be obtained under the case of fewer elements used in simulation of CAMs, even there being some elements with poor quality.