Is Synthetic Composite Bone a Substitute for Natural Bone in Screw Bending Tests?

Author(s):  
Thomas P. James ◽  
Brendan A. Andrade

Composite replica bones have been used extensively for biomechanical studies. These studies normally rely upon the overall tensile, compressive, and bending strength of large replica bones, such as the tibia and femur. In this study, highly localized behavior of composite bone was scrutinized by examining the material’s response to cortical screws in bending. Of interest was localized deformation of the composite material as compared to the response of natural bone under similar loading conditions. Cortical screw deflection in a laminated composite bone was compared to deflection in a bovine bone under quasi-static loading. The laminated composite bone consisted of short glass fiber reinforced epoxy as a cortical bone substitute, while polyurethane foam was used as a cancellous bone substitute. A new laser projection method was used to make comparative measurements of the slope of the screw head near to the applied load. Initial results indicate that composite bone is a reliable substitute for natural bone in quasi-static studies of cortical screw deflection.

2013 ◽  
Vol 575-576 ◽  
pp. 194-197
Author(s):  
Xiao Bing Li ◽  
Guo Yin Zu ◽  
Ping Wang

This paper is aim to investigate the interfacial effect on the bending property of Al/Cu/Al laminated composite produced by the asymmetrical roll bonding and annealing. The interfacial microstructure was observed by scanning electron microscope, and the three-point bending tests were conducted at room temperature. It is found that the interfacial layer near the faster roll is about 1 μm thickness and continuous, and the bending strength is increased by 4.4% in comparison with the interface near the slower roll. The results demonstrate that the shear deformation during asymmetrical roll bonding causes a severe interfacial fracture and makes a good interfacial bonding. The increase of bending load is ascribed to the interfacial improvement.


Author(s):  
E Kara ◽  
A Kurşun ◽  
MR Haboğlu ◽  
HM Enginsoy ◽  
H Aykul

The joining techniques of lightweight and strong materials in the transport industry (e.g. automotive, aerospace, shipbuilding industries) are very important for the safety of the entire structure. In these industries, when compared with other joining methods, the use of adhesively bonded joints presents unique properties such as greater strength, design flexibility, and reduction in fuel consumption, all thanks to low weight. The aim of this study was the analysis of the tensile fatigue behavior of adhesively bonded glass fiber/epoxy laminated composite single-lap joints with three different specimen types including 30, 40 and 50 mm overlap lengths. In this study, composite adherents were manufactured via vacuum-assisted resin transfer molding and were bonded using Loctite 9461 A&B toughened epoxy adhesive. The effect of a surface treatment method on the bonding strength was considered and it led to an increment of about 40%. A numerical analysis based on a finite element model was performed to predict fatigue life curve, and the predicted results showed good agreement with the experimental investigation.


2021 ◽  
pp. 002199832110200
Author(s):  
H Ersen Balcıoğlu ◽  
Raif Sakin ◽  
Halit Gün

Fiber-reinforced laminated composite is often used in harsh environments that may affect their static stability and long-term durability as well as residual strength. In this study, the effect of heavy chemical environments such as acid and alkaline and retaining time for these environments on flexural strength and flexural fatigue behavior of carbon/epoxy laminated composites were investigated. In this context, carbon/epoxy was retained into an acidic and alkaline solution having 5%, 15%, and 25% concentration by weight for 1–4 months. Fatigue behavior of carbon/epoxy was determined under dynamic flexural load, which corresponds to 80%, 70%, 60%, 50%, and 40% of static three-point bending strength of the test sample. SEM image of damaged specimens was taken to describe the failure mechanism of damage which occurs after fatigue. Also, to better understand environmental condition on the fatigue life, results were compared with results of carbon/epoxy laminated composites, which were not retained into any environments (unretained). The test results showed that the solution type, solution concentration, and retaining time caused noticeable changes in the static and dynamic strengths of carbon/epoxy laminated composites.


2010 ◽  
Vol 89 (4) ◽  
pp. 411-416 ◽  
Author(s):  
M. Yamada ◽  
T. Ueno ◽  
H. Minamikawa ◽  
N. Sato ◽  
F. Iwasa ◽  
...  

Lack of cytocompatibility in bone substitutes impairs healing in surrounding bone. Adverse biological events around biomaterials may be associated with oxidative stress. We hypothesized that a clinically used inorganic bone substitute is cytotoxic to osteoblasts due to oxidative stress and that N-acetyl cysteine (NAC), an antioxidant amino acid derivative, would detoxify such material. Only 20% of rat calvaria osteoblasts were viable when cultured on commercial deproteinized bovine bone particles for 24 hr, whereas this percentage doubled on bone substitute containing NAC. Intracellular ROS levels markedly increased on and under bone substitutes, which were reduced by prior addition of NAC to materials. NAC restored suppressed alkaline phosphatase activity in the bone substitute. Proinflammatory cytokine levels from human osteoblasts on the bone substitute decreased by one-third or more with addition of NAC. NAC alleviated cytotoxicity of the bone substitute to osteoblastic viability and function, implying enhanced bone regeneration around NAC-treated inorganic biomaterials.


2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Lara Schorn ◽  
Tim Fienitz ◽  
Kathrin Berndsen ◽  
Norbert R. Kübler ◽  
Henrik Holtmann ◽  
...  

Abstract Background The aim of this study was to compare new bone formation, resorbed bone matrix, and fibrous enclosed residual bone substitute material in laterally augmented alveolar bone defects using allogeneic, pre-treated and cleaned human bone blocks (tested in dogs, therefore considered to be xenogeneic), and pre-treated and cleaned bovine cancellous bone blocks, both with and without a collagen membrane in order to evaluate their augmentative potential. Methods Thirty-two critical size horizontal defects were prepared in the mandible of 4 adult foxhound dogs (8 per dog, 4 on each side). After 3 months of healing, the defects were laterally augmented in a split-mouth-design with either human (HXB) or bovine solvent-preserved bone blocks (BXB). Afterwards, defects were randomly covered with a bovine collagenous membrane (HXB + M, BXB + M). After a healing interval of 6 months, percentages of new bone formation, resorbed bone matrix, and fibrous enclosed residual bone substitute material were compared. Results Results showed little new bone formation of up to 3.7 % in human bone blocks (HXB 3.7 % ± 10.2, HXB + M 0.3 %± 0.4, BXB, 0.1 % ± 0.8, BXB + M 2.6 % ± 3.2, p = > 0.05). Percentages of fibrous encapsulation were higher in human bone blocks than in bovine bone blocks (HXB 71.2 % ± 8.6, HXB + M 73.71 % ± 10.6, BXB, 60.5 % ± 27.4, BXB + M 52.5 % ± 28.4, p = > 0.05). Resorption rates differed from 44.8 % in bovine bone blocks covered with a membrane to 17.4 % in human bone blocks (HXB 17.4 % ± 7.4, HXB + M 25.9 % ± 10.7, BXB, 38.4 % ± 27.2, BXB + M 44.8 % ± 29.6, p = > 0.05). The use of additional membranes did not significantly affect results. Conclusions Within its limitations, results of this study suggest that solvent-preserved xenogenic human and bovine bone blocks are not suitable for lateral bone augmentation in dogs. Furthermore, defect coverage with a membrane does not positively affect the outcome.


Author(s):  
Teoh Hui Xin ◽  
◽  
Norazman Mohamad Nor ◽  
Mohammed Alias Yusof ◽  
◽  
...  

Bamboo is an eco-friendly material, it can be used in various applications such as bamboo housing, bamboo bridges, bamboo scaffolding, ply bamboo, bamboo furniture, and for defence applications. It has various advantages to be used as structural material. However, it has weaknesses such as crushing failure under extreme loading that need to be addressed. The objective of this research is to enhance bamboo bearing and bending capacity using various stiffeners. Experimental work done is to investigate the compressive strength, bending strength, bearing strength and tensile strength of raw local bamboo. Further analysis includes bending and bearing strength of raw bamboo and strengthen bamboo using Glass Fiber Reinforced Polymer (GFRP) and Polyurethane (PU) Foams. From the test done, the bearing strength of raw bamboo Semantan with node is between 2.61 MPa to 3.14 MPa and for raw bamboo Semantan without node is between 0.28 MPa to 0.82 MPa, average bending strength of raw bamboo Semantan is 59 MPa. For strengthen bamboo with 4 layers of Glass Fiber Reinforced Polymer, the bearing strength without node is between 1.59 MPa to 2.38 MPa, and the average bending strength is 62 MPa which is about 5% higher than raw bamboo.


2016 ◽  
Vol 12 (3) ◽  
Author(s):  
Uiatan Aguiar Nogueira ◽  
Matilde Batista Melo ◽  
Daniel De Lima Araujo

RESUMO: A Análise de elementos estruturais, realizadas durante as etapas de projeto de uma estrutura, é parte fundamental para garantia de bom desempenho e estabilidade do sistema estrutural. Na execução de algumas estruturas, como as coberturas em edificações, é usual o emprego de perfis leves de aço formados a frio devido ao seu baixo peso. Esta pesquisa tem por objetivo avaliar a eficiência estrutural desses perfis quando comparados, por exemplo, aos perfis soldados compactos. Para tanto, foram realizados ensaios de flexão em quatro vigas biapoiadas submetidas a duas forças concentradas, de forma a se obter flexão pura no meio do vão das vigas. Estas foram instrumentadas para a determinação da sua rigidez e da sua resistência à flexão. A principal contribuição deste trabalho é demonstrar a eficiência estrutural de perfis formados a frio em seção caixa submetidos à flexão em comparação com perfis de seção tipo “H” soldados. ABSTRACT: The analysis of structural elements, in a structure’s design, is an essential step to ensure good performance and stability of the structural system. In any types of structures, such as roofing in buildings, it’s usual using cold-formed steel beams due to their small weight. This research seeks to evaluate the structural efficiency of cold-formed steel beams when compared, for example, to compact welded steel beams. Thus, bending tests were performed in four simply supported beams submitted to two concentrated loads, in order to obtain pure flexure at the mid-span of the beams. These beams were instrumented for the determination of their rigidity and bending strength. The results showed that the cold-formed steel beam, box-shaped, presented structural efficiency similar to the welded steel beam “H” shaped.


2007 ◽  
Vol 353-358 ◽  
pp. 345-348
Author(s):  
Ki Woo Nam ◽  
B.G. Ahn ◽  
M.K. Kim ◽  
C.S. Son ◽  
Jin Wook Kim ◽  
...  

The optimized conditions of pressureless sintering were investigated in order to obtain the bending strength and the elastic wave signal of Al2O3 composite ceramics for textiles machinery. As sintering conditions, a temperature range from 1400°C to 1700°C and time from 30 minutes to 150 minutes were applied. Three-point bending tests were conducted on the sintered materials to obtain the strength property. From the test results, the optimum sintering condition was 1600°C, 100 minutes. Al2O3 composite ceramics showed that the elastic wave signal characteristics had a regular correlativity between the optimum sintering temperature and time as well as the maximum bending strength.


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