Fracture mechanism and mechanical properties of porous HA/PLCL and HA/PLLA sandwich composite beams.

In Vitro Model

Research Institute for Applied Mechanics, Kyushu University, Fukuoka, Japan.

Published: November 2023

Previously, we have developed a novel porous hydroxyapatite/poly l-lactic-co-caprolactone (HA/PLCL) composite sandwich beam as a new scaffold material for bone regeneration. This work presents the study of bending fracture mechanisms and microdamage of porous hydroxyapatite/poly L-lactic-acid (HA/PLLA) sandwich beam, in comparison to the previous developed HA/PLCL sandwich beam. Both beams were fabricated using the sandwich method in which the single porous composite beams were layered in between two porous polymer layers of their kind. Three-point bending tests were performed to assess their mechanical properties, and their microstructures along with the damage mechanisms were examined using field emission-scanning electron microscope (FE-SEM). Their crystalline structures and thermal properties were analyzed using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) analysis, and differential scanning calorimetry (DSC) measurements. The microdamage and fracture mechanisms were then characterized by stepwise crack formations. It was found that HA/PLLA composite sandwich beam possessed higher mechanical properties compared to HA/PLCL sandwich beam, resulting from higher stiffness of PLLA polymer. PLCL layer showed a vast ductile fracture, with elongated PLCL strips, while the fracture surfaces observed on the PLLA layer have a relatively brittle fracture pattern with some polymeric pores that were still visible. Three stages of damage were observed on both beams with different locations of crack initiation, indicating that different polymer materials do affect the fracture behavior of each beam.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC11756499PMC
http://dx.doi.org/10.1007/s44164-023-00053-0DOI Listing

Publication Analysis

Top Keywords

sandwich beam
20
mechanical properties
12
ha/plla sandwich
8
composite beams
8
porous hydroxyapatite/poly
8
composite sandwich
8
fracture mechanisms
8
ha/plcl sandwich
8
fracture
7
sandwich
7

Similar Publications

Experimental Study on Mechanical Performance of Single-Side Bonded Carbon Fibre-Reinforced Plywood for Wood-Based Structures.

Materials (Basel)

January 2025

Department of Integrated Design and Tribology Systems, Faculty of Mechanics and Technology, Rzeszów University of Technology, ul. Kwiatkowskiego 4, 37-450 Stalowa Wola, Poland.

In addition to the traditional uses of plywood, such as furniture and construction, it is also widely used in areas that benefit from its special combination of strength and lightness, particularly as a construction material for the production of finishing elements of campervans and yachts. In light of the current need to reduce emissions of climate-damaging gases such as CO, the use of lightweight construction materials is very important. In recent years, hybrid structures made of carbon fibre-reinforced plastics (CFRPs) and metals have attracted much attention in many industries.

View Article and Find Full Text PDF

Nanoparticles are essential for energy storage, catalysis, and medical applications, emphasizing their accurate chemical characterization. However, atom probe tomography (APT) of nanoparticles sandwiched at the interface between an encapsulating film and a substrate poses difficulties. Poor adhesion at the film-substrate interface can cause specimen fracture during APT, while impurities may introduce additional peaks in the mass spectra.

View Article and Find Full Text PDF

Multiscale Concurrent Topology Optimization and Mechanical Property Analysis of Sandwich Structures.

Materials (Basel)

December 2024

Institute of Applied Mechanics, College of Aeronautics and Astronautics, Taiyuan University of Technology, Taiyuan 030024, China.

Based on the basic theoretical framework of the Bi-directional Evolutionary Structural Optimization method (BESO) and the Solid Isotropic Material with Penalization method (SIMP), this paper presents a multiscale topology optimization method for concurrently optimizing the sandwich structure at the macro level and the core layer at the micro level. The types of optimizations are divided into macro and micro concurrent topology optimization (MM), macro and micro gradient concurrent topology optimization (MMG), and macro and micro layered gradient concurrent topology optimization (MMLG). In order to compare the multiscale optimization method with the traditional macroscopic optimization method, the sandwich simply supported beam is illustrated as a numerical example to demonstrate the functionalities and superiorities of the proposed method.

View Article and Find Full Text PDF

Lithium niobate thin film electro-optic modulator.

Nanophotonics

April 2024

The Key Laboratory of Weak-Light Nonlinear Photonics, Ministry of Education, School of Physics and TEDA Applied Physics Institute, Nankai University, Tianjin 300071, People's Republic of China.

The linear electro-optic effect offers a valuable means to control light properties via an external electric field. Lithium niobate (LN), with its high electro-optic coefficients and broad optical transparency ranges, stands out as a prominent material for efficient electro-optic modulators. The recent advent of lithium niobate-on-insulator (LNOI) wafers has sparked renewed interest in LN for compact photonic devices.

View Article and Find Full Text PDF

In this work, we demonstrate the use of two-photon polymerization direct laser writing in the production of continuously tuneable optical vortex beam (OV) generators in a liquid crystal (LC) layer sandwiched between glass substrates. Results are presented that show how an OV generator can be inscribed into a 20 μm-thick LC layer and how the order of the OV beam can be tuned with the application of a voltage. Importantly, only a single pair of electrodes is needed to tune the order of the vortex as the required phase profile is generated through the 3D structuring of the polymer network using the laser writing process.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!