scholarly journals Performance of glue laminated timber beams composed of sengon wood (Albizia falcatara) and coconut wood (Cocos nucifera) with nylon-threads reinforcement

2018 ◽  
Vol 195 ◽  
pp. 02029
Author(s):  
Kusnindar ◽  
Sri Murni Dewi ◽  
Agoes Soehardjono ◽  
Wisnumurti
Keyword(s):  
Shear Strength ◽  
Elastic Modulus ◽  
Cocos Nucifera ◽  
Bending Test ◽  
Type I ◽  
Type Ii ◽  
Test Results ◽  
Three Point Bending ◽  
External Reinforcement ◽  
Timber Beams

This paper aims to describe the performance of mix-glue laminated timber beams that are given a nylon strapping as external reinforcement with the three-point bending test to three groups of beams based on the span-to-depth ratio, i.e.: G11, G8, and G5 groups. Each group consists of three types of lamination compositions, namely: Type I, whole lamination consists of sengon wood; Type II, the placement of the coconut wood lamination as the outermost; Type III, similar to type II with added nylon straps with a distance of 5 mm. The bending test results show differences in elastic modulus, flexural strength and shear strength of the glue-laminated timber beams. Based on the comparison of glulam beams consisting of six laminations of sengon wood it was found that the placement of the coconut wood as the outermost lamination succeeded in increasing the elastic modulus, the flexural and shear strength of beams by 28%, 13%, and 34%, respectively. In addition, the reinforcement with nylon straps results in the modulus of elasticity, bending and shear strength of glulam to increase by by 41%, 2%, and 49% respectively.

Experimental and Numerical Investigation of Critical Buckle Load of Composite Specimens

2015 ◽  
Vol 732 ◽  
pp. 85-90
Author(s):  
Lukáš Bek ◽  
Radek Kottner ◽  
Jan Krystek ◽  
Tomáš Kroupa
Keyword(s):  
Static Analysis ◽  
Glass Fibre ◽  
Large Deformations ◽  
Bending Test ◽  
Test Results ◽  
Beam Test ◽  
Three Point Bending ◽  
Box Beams ◽  
Buckle Beam ◽  
Thin Walled

Different carbon and glass fibre strips were subjected to the double clamp buckle beam test. Furthermore, thin-walled glass fibre box-beams were subjected to the three-point bending test. Results of experiments were compared to different numerical simulations using buckling analysis or static analysis considering large deformations.

Cryogenic Interlaminar Properties of PBO Fiber/Epoxy Composites

2011 ◽  
Vol 391-392 ◽  
pp. 1445-1449
Author(s):  
Chun Hua Zhang ◽  
Shi Lin Luan ◽  
Xiu Song Qian ◽  
Bao Hua Sun ◽  
Wen Sheng Zhang
Keyword(s):  
Liquid Nitrogen ◽  
Room Temperature ◽  
Liquid Nitrogen Temperature ◽  
Epoxy Composites ◽  
Bending Test ◽  
Test Results ◽  
Sem Images ◽  
Three Point Bending ◽  
Pbo Fiber ◽  
Interlaminar Shear

The influences of low temperature on the interlaminar properties for PBO fiber/epoxy composites have been studied at liquid nitrogen temperature (77 K) in terms of three point bending test. Results showed that the interlaminar shear strength at 77 K were significantly higher than those at room temperature (RT). For the analysis of the test results, the tensile behaviors of epoxy resin at both room temperature and liquid nitrogen temperature were investigated. The interface between fiber and matrix was observed using SEM images.

Preparation and Research on the Lateral Elastic Modulus of the MnO2 Nanowires

2013 ◽  
Vol 662 ◽  
pp. 84-87
Author(s):  
Yong Jiang ◽  
Jian Cheng Deng ◽  
Yan Huai Ding ◽  
Jiu Ren Yin ◽  
Ping Zhang
Keyword(s):  
Elastic Modulus ◽  
Crystal Form ◽  
Bending Test ◽  
X Ray Diffraction ◽  
Nanowire Diameter ◽  
X Ray ◽  
Three Point Bending ◽  
Force Microscopy ◽  
Atomic Force ◽  
Mno2 Nanowires

MnO2 nanowires with large aspect ratio were successfully synthesized via a hydrothermal method. In this method, Mn(NO3)2 was as a source of manganese and NH4NO3 as an oxidant. The structure and morphology of the MnO2 nanowires were characterized by X ray diffraction (XRD) and scanning electron microscope (SEM). Their lateral elastic modulus was characterized via a nanoscale three-point bending test by atomic force microscopy (AFM) equipped with picoforce. The results indicate that the crystal form of MnO2 was β-MnO2. The elastic modulus of the nanowires decreased with the increase in nanowire diameter. This elastic modulus was in the range of 33.36-77.84GPa as the diameter ranged from 240 to 185nm.

Shear strength of disturbed regions with corroded stirrups in reinforced concrete beams

2010 ◽  
Vol 37 (8) ◽  
pp. 1045-1056 ◽  
Author(s):  
Christopher Suffern ◽  
Ahmed El-Sayed ◽  
Khaled Soudki
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Corrosion Damage ◽  
Reinforced Concrete Beams ◽  
Test Results ◽  
Accelerated Corrosion ◽  
Damage Level ◽  
Three Point Bending ◽  
Shear Span

This paper reports experimental data on the structural performance of disturbed regions in reinforced concrete beams with corrosion damage to the embedded steel stirrups. A total of 15 reinforced concrete beams were constructed and tested. The test beams were 350 mm deep, 125 mm wide, and 1850 mm long. The beams were tested in three-point bending under a simply supported span of 1500 mm. Nine beams had the embedded stirrups subjected to accelerated corrosion. The test variables were the corrosion damage level and the shear span-to-depth ratio. The test results indicated that the corroded beams exhibited reduced shear strength in comparison to the uncorroded control specimens. The shear strength reduction was up to 53%. Furthermore, the reduction in shear strength due to the corrosion was found to be greater at smaller shear span-to-depth ratios.

scholarly journals Screw head plugs increase the fatigue strength of stainless steel, but not of titanium, locking plates

2018 ◽  
Vol 7 (12) ◽  
pp. 629-635 ◽  
Author(s):  
L-W. Hung ◽  
C-K. Chao ◽  
J-R. Huang ◽  
J. Lin
Keyword(s):  
Stainless Steel ◽  
Fatigue Strength ◽  
Steel Plates ◽  
Bending Test ◽  
Type I ◽  
Locking Plates ◽  
Type Ii ◽  
Screw Head ◽  
Type Iii ◽  
Four Point Bending

ObjectivesScrew plugs have been reported to increase the fatigue strength of stainless steel locking plates. The objective of this study was to examine and compare this effect between stainless steel and titanium locking plates.MethodsCustom-designed locking plates with identical structures were fabricated from stainless steel and a titanium alloy. Three types of plates were compared: type I unplugged plates; type II plugged plates with a 4 Nm torque; and type III plugged plates with a 12 Nm torque. The stiffness, yield strength, and fatigue strength of the plates were investigated through a four-point bending test. Failure analyses were performed subsequently.ResultsFor stainless steel, type II and type III plates had significantly higher fatigue strength than type I plates. For titanium, there were no significant differences between the fatigue strengths of the three types of plates. Failure analyses showed local plastic deformations at the threads of screw plugs in type II and type III stainless steel plates but not in titanium plates.ConclusionThe screw plugs could increase the fatigue strength of stainless steel plates but not of titanium plates. Therefore, leaving screw holes open around fracture sites is recommended in titanium plates. Cite this article: L-W. Hung, C-K. Chao, J-R. Huang, J. Lin. Screw head plugs increase the fatigue strength of stainless steel, but not of titanium, locking plates. Bone Joint Res 2018;7:629–635. DOI: 10.1302/2046-3758.712.BJR-2018-0083.R1.

Complementary Use of Inductive Test and Bending Test for the Characterization of SFRC

2014 ◽  
Vol 580-583 ◽  
pp. 2213-2219 ◽  
Author(s):  
Lin Liao ◽  
Sergio Cavalaro ◽  
Albert de la Fuente ◽  
Antonio Aguado
Keyword(s):  
Steel Fibre ◽  
Fibre Orientation ◽  
Bending Test ◽  
Fibre Reinforced Concrete ◽  
Test Results ◽  
Flexural Behaviour ◽  
Steel Fibre Reinforced Concrete ◽  
Three Point Bending ◽  
Experimental Campaign

Many researches have been conducted in past decades for promoting the application of steel fibre reinforced concrete (SFRC), either conventional or self-compacting. However, the differences of post-crack behaviour and the properties of these two types of concrete remains unclear. The objective of this paper is to analyse such differences in terms of flexural behaviour, fibre orientation and contribution as well as the fibre content. For that, an extensive experimental campaign was carried out. In total 3 mixes of self-compacting and 3 mixes with traditional concrete were produced with the nominal fibre contents of 30kg/m3, 45kg/m3 and 60kg/m3. In each series, specimens were produces and characterized by three point bending test (code EN 14651) and inductive test. The results illustrate how fibre orientation and distribution justify the differences in the mechanical behaviour of the materials and the scatter of the bending test results.

scholarly journals Photoreactive UV-Crosslinkable Acrylic Pressure-Sensitive Adhesives (PSA) Containing Multifunctional Photoinitiators

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4413
Author(s):  
Marcin Bartkowiak ◽  
Zbigniew Czech ◽  
Hyun-Joong Kim ◽  
Gyu-Seong Shim ◽  
Małgorzata Nowak ◽  
...  
Keyword(s):  
Shear Strength ◽  
Ultraviolet Radiation ◽  
Type I ◽  
Type Ii ◽  
Pressure Sensitive Adhesives ◽  
Crosslinking Process ◽  
Pressure Sensitive ◽  
Peel Adhesion ◽  
The One ◽  
Uv Technology

The use of ultraviolet radiation (UV) technology for the crosslinking of acrylic pressure-sensitive adhesives (PSA) is the one of various crosslinking methods, being the alternative to the conventional crosslinking process of solvent-based acrylic systems. It also requires a photoinitiator to absorb the impinging UV and induce photocrosslinking. As previously mentioned, a photoinitiator is one of the important and necessary components in UV-inducted crosslinking of acrylic pressure-sensitive adhesives. The activity of multifunctional conventional saturated photoinitiators of type I and type II, especially benzophenone-based in the photoreactive UV-crosslinkable acrylic PSA was described. The effect of the multifunctional type-II photoinitiators on the acrylic PSA, such as tack, peel adhesion and shear strength were summarized.

Effect of Filler Content and Waiting time Before Light-Curing on Mechanical Properties of Dual-Cured Cement

2020 ◽  
Vol 2 (1) ◽  
pp. 45-52
Author(s):  
Ana C. de Assunção Oliveira ◽  
Sandro Griza ◽  
Rafael R. de Moraes ◽  
André L. Faria-e-Silva
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Flexural Strength ◽  
Waiting Time ◽  
Filler Content ◽  
Bending Test ◽  
Resin Cements ◽  
Three Point Bending ◽  
Light Curing ◽  
Curing Procedure

Objective:: To investigate the effect of filler content and the time spent before light-curing on mechanical properties of dual-cured cement. Methods:: Experimental dual-cured resin cements were formulated with 60, 65 or 68wt% of filler. The viscosity of experimental cement was measured using a digital viscometer. Bar-shaped specimens (25 x 2 x 2 mm) were fabricated, while the light-curing was started immediately or 5 minutes after the insertion of cement into the mold (n = 7). A three-point bending test was performed and the values of flexural strength and elastic modulus were measured. The Vickers hardness of fractured specimens was measured on the surface of the cement. Data from viscosity were submitted to oneway ANOVA, while the data from mechanical properties were analyzed by two-way ANOVA. All pair-wise comparisons were performed using Tukey’s test (α = 0.05). Results:: The experimental cement with 68wt% of filler showed the highest viscosity and those with 60wt% showed the the lowest viscosity. Irrespective of the time spent before light-curing, the cement with 65wt% of filler presented the highest values of flexural strength and elastic modulus. The addition of 60wt% of filler resulted in the lowest elastic modulus, while 68wt% of filler resulted in lowest flexural strength. Regarding the hardness, the cement with 68wt% of filler showed the highest values, while there was no difference between 60 and 65wt% of filler. Conclusion:: Filler content affected the mechanical properties of the experimental cement and this effect did not depend on the waiting time before the light-curing procedure.

scholarly journals Experimental study of the mechanical behavior of self-compacting concrete based on fracture mechanics

2017 ◽  
Vol 10 (3) ◽  
pp. 744-759
Author(s):  
G. O. RIBEIRO ◽  
P. C. GUETTI ◽  
P. SERNA
Keyword(s):  
Compressive Strength ◽  
Fracture Mechanics ◽  
Mechanical Behavior ◽  
Process Zone ◽  
Physical Nonlinearity ◽  
Bending Test ◽  
Maximum Diameter ◽  
Test Results ◽  
Self Compacting Concrete ◽  
Three Point Bending

ABSTRACT Considering the physical nonlinearity of concrete and the fundamentals of fracture mechanics for quasi-brittle materials, the objective of this study was to determine the fracture energy and the length of the fracture process zone (FPZ) as well as the modulus of elasticity, the tensile strength and the compressive strength of self-compacting concrete (SCC) to characterize its mechanical behavior. A series of tests, including a three-point bending test of SCC and conventional vibrated concrete (CVC) specimens, with a notch at mid-span, and tensile and compressive tests were performed. The mechanical parameters obtained from the CVC specimens were considered as a comparative reference. The effect of the following variables was evaluated and considered at two levels: compressive strength (30 and 50 MPa), granular composition (fine and coarse particle size) and maximum diameter of the aggregate (12 and 20 mm). The effect of these variables on the mechanical behaviors of the SCC specimens was evaluated based on the test results of specimens of four types of concrete, which were obtained from the combination of the variables. The bending tests were performed according to the RILEM TC 89-FMT recommendations, which are based on the size-effect method.

Fracture Parameters of Fly Ash and GGBS Based Geopolymer Concrete

2015 ◽  
Vol 764-765 ◽  
pp. 1090-1094
Author(s):  
Tippabhotla D. Gunneswara Rao ◽  
P. Alfrite ◽  
G. Mallikarjuna Rao ◽  
Mudimby Andal
Keyword(s):  
Fly Ash ◽  
Construction Material ◽  
Bending Test ◽  
Geopolymer Concrete ◽  
Test Results ◽  
Conventional Concrete ◽  
Three Point Bending ◽  
Beam Depth ◽  
New Construction ◽  
Source Materials

Geopolymer concrete (GPC) is a new construction material in which cement is totally replaced by calcined source materials fly ash and GGBS. Geopolymer utilization reduces or eliminates the use of cement whose production produces a lot of carbon dioxide. Usually fly ash as a source material for the geopolymer. The behavior of GPC has to be studied in detail to check its suitability in construction industry. In the present study, the fracture behavior of geopolymer concrete is investigated and compared. Three-point bending test on notched prisms with a/d (notch depth/beam depth) ratios 0.1, 0.15, 0.2 are considered. The values of Critical load, fracture toughness, fracture energy and ductility are presented. The test results of total of 27prisms, 6cubes, 18 cylinders with M30 grade geopolymer concrete and conventional concrete (OPC) of same grade are presented in this paper. The test results indicated that the characteristic length of GPC is about 25% more than that of conventional concrete.

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