scholarly journals Mechanical properties of laterally loaded threaded rods embedded in softwood

2021 ◽  
Author(s):  
Haris Stamatopoulos ◽  
Francesco Mirko Massaro ◽  
Jalal Qazi
Keyword(s):  
Mechanical Properties ◽  
Core Diameter ◽  
Bending Tests ◽  
Three Point Bending ◽  
The Core ◽  
Threaded Fasteners ◽  
Characteristic Values ◽  
Strength And Stiffness ◽  
Screw Threads ◽  
Laterally Loaded

AbstractAt present, the mechanical properties of laterally loaded threaded fasteners with large diameters embedded in timber elements remain unknown. An experimental study of laterally loaded threaded rods with wood screw threads embedded perpendicular to grain in softwood elements (spruce and pine glulam and spruce LVL) is presented in this paper. Embedment tests with the load acting parallel and perpendicular to grain were carried out and the embedment strength and stiffness were quantified. For some test series, the experimental embedment strengths were lower compared to the predictions according to Eurocode 5 in terms of both mean and characteristic values. This finding indicates that the predictions by Eurocode 5 are not always conservative. To investigate the effect of the thread, additional series of embedment tests were carried out with smooth dowels featuring a diameter approximately equal to the core diameter of the threaded rods. Finally, the yielding moment of threaded rods was quantified based on a series of three-point bending tests of threaded rods. The experimentally determined yielding moment was significantly higher than the prediction of Eurocode 5.

Experimental investigation on Iroko wood used in shipbuilding

2016 ◽  
Vol 231 (1) ◽  
pp. 128-139 ◽  
Author(s):  
V Bucci ◽  
P Corigliano ◽  
V Crupi ◽  
G Epasto ◽  
E Guglielmino ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Strength Class ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Bending Tests ◽  
Three Point Bending ◽  
Test Pieces ◽  
Hardwood Species ◽  
Glued Laminated Timber ◽  
Strength And Stiffness

The paper deals with investigations about mechanical properties of Iroko, a hardwood species used for structures in shipbuilding as glued laminated timber. Experimental tests have been carried out to assess strength, stiffness and density of Iroko in accordance with current EN Standards. All the results obtained by tensile and three-point bending tests, along with the statistical analyses performed to define the characteristics values of some mechanical properties, are reported in the paper. These values allowed to assign the strength class, reported in EN 338 Standard, to the investigated Iroko wood population. The experiments have taken into account both solid timber strips and scarf-jointed strips, in order to evaluate the influence of such a type of joint, which is widely used in wooden shipbuilding on strength and stiffness. Eventually, peculiar investigations have been carried out to analyse the failure mode of some test pieces through special experimental techniques: three-dimensional computed tomography and infrared thermography.

scholarly journals Comparison of Mechanical Properties of Hemp-Fibre Biocomposites Fabricated with Biobased and Regular Epoxy Resins

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5720 ◽  
Author(s):  
Vicente Colomer-Romero ◽  
Dante Rogiest ◽  
Juan Antonio García-Manrique ◽  
Jose Enrique Crespo
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resins ◽  
Raw Materials ◽  
Green Composites ◽  
Bending Tests ◽  
Three Point Bending ◽  
Reinforced Plastics ◽  
Structural Applications ◽  
Glass Fibre Reinforced ◽  
Glass Fibre Reinforced Plastics

Bio- and green composites are mainly used in non-structural automotive elements like interior panels and vehicle underpanels. Currently, the use of biocomposites as a worthy alternative to glass fibre-reinforced plastics (GFRPs) in structural applications still needs to be fully evaluated. In the current study, the development of a suited biocomposites started with a thorough review of the available raw materials, including both reinforcement fibres and matrix materials. Based on its specific properties, hemp appeared to be a very suitable fibre. A similar analysis was conducted for the commercially available biobased matrix materials. Greenpoxy 55 (with a biocontent of 55%) and Super Sap 100 (with a biocontent of 37%) were selected and compared with a standard epoxy resin. Tensile and three-point bending tests were conducted to characterise the hemp-based biocomposite.

scholarly journals Influence of the Infill Orientation on the Properties of Zirconia Parts Produced by Fused Filament Fabrication

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3158 ◽  
Author(s):  
Santiago Cano ◽  
Tanja Lube ◽  
Philipp Huber ◽  
Alberto Gallego ◽  
Juan Alfonso Naranjo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Complex Geometries ◽  
Fused Filament Fabrication ◽  
Moisture Evaporation ◽  
Bending Tests ◽  
Three Point Bending ◽  
Different Types ◽  
Fill Pattern ◽  
The Many

The fused filament fabrication (FFF) of ceramics enables the additive manufacturing of components with complex geometries for many applications like tooling or prototyping. Nevertheless, due to the many factors involved in the process, it is difficult to separate the effect of the different parameters on the final properties of the FFF parts, which hinders the expansion of the technology. In this paper, the effect of the fill pattern used during FFF on the defects and the mechanical properties of zirconia components is evaluated. The zirconia-filled filaments were produced from scratch, characterized by different methods and used in the FFF of bending bars with infill orientations of 0°, ±45° and 90° with respect to the longest dimension of the specimens. Three-point bending tests were conducted on the specimens with the side in contact with the build platform under tensile loads. Next, the defects were identified with cuts in different sections. During the shaping by FFF, pores appeared inside the extruded roads due to binder degradation and or moisture evaporation. The changes in the fill pattern resulted in different types of porosity and defects in the first layer, with the latter leading to earlier fracture of the components. Due to these variations, the specimens with the 0° infill orientation had the lowest porosity and the highest bending strength, followed by the specimens with ±45° infill orientation and finally by those with 90° infill orientation.

Graded-Index and Single-Mode Polymer Optical Fibers

1992 ◽  
Vol 247 ◽  
Author(s):  
Yasuhiro Koike
Keyword(s):  
Mechanical Properties ◽  
Optical Fibers ◽  
Single Mode ◽  
Polymer Optical Fiber ◽  
Core Diameter ◽  
Graded Index ◽  
The Core ◽  
High Bandwidth ◽  
Polymer Optical Fibers ◽  
First Time

ABSTRACTHigh-bandwidth graded-index (GI) polymer optical fiber (POF) and single-mode POF with good mechanical properties were successfully obtained by our interfacial-gel polymerization technique. The bandwidth of the GI POF is about 1 GHz · km which is two hundred times larger than that of the conventional step-index (SI) POF. The minimum attenuation of transmission is 56 dB/km at 688-nm wavelength and 94 dB/km at 780-nm wavelength. The single-mode POF in which the core diameter was 3–15 μ m and the attenuation of transmission was 200 dB/km at 652-nm wavelength was successfully obtained for the first time.

Mechanical properties of several nickel-titanium alloy wires in three-point bending tests

1999 ◽  
Vol 115 (4) ◽  
pp. 390-395 ◽  
Author(s):  
Hirokazu Nakano ◽  
Kazuro Satoh ◽  
Robert Norris ◽  
Tomoaki Jin ◽  
Tetsuya Kamegai ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Nickel Titanium ◽  
Bending Tests ◽  
Three Point Bending

Study on Automobile Body Performance of Honeycomb Sandwich Composite Material

2012 ◽  
Vol 567 ◽  
pp. 146-149 ◽  
Author(s):  
Xue Mei Fan ◽  
Jian Feng Wang ◽  
Cheng Jin Duan ◽  
Xiang Xin Xia ◽  
Zhao Hui Wang
Keyword(s):  
Mechanical Properties ◽  
Sandwich Structure ◽  
Testing Machine ◽  
Sandwich Composite ◽  
Element Analysis ◽  
Bending Tests ◽  
Three Point Bending ◽  
Honeycomb Sandwich ◽  
Core Thickness ◽  
Honeycomb Sandwich Structure

In order to analyze the mechanical properties of Carbon/epoxy facings-Aluminum honeycomb sandwich structure, we simulated panels of different layers and core thickness using ABAQUS finite element analysis program. And three-point bending tests and shear tests were made on the same panels using electronic universal testing machine. In addition, we also made the same three-point bending tests on steel tubes to get a comparison with honeycomb sandwich panels. It could be seen that, the simulated results were basically identified with experimental results. The results indicated that core thickness played an important role in the panels’ bulking modulus, and number of carbon fiber layers decided the shear strength. As a whole, honeycomb sandwich structure was suitable for use in the car body with good mechanical properties under premise of lighter.

Effects of Bending Cyclic Load on Mechanical Properties of 2D Carbon Cloth Laminated C/C Composites

2012 ◽  
Vol 157-158 ◽  
pp. 792-795 ◽  
Author(s):  
Xi Yang ◽  
He Jun Li ◽  
Kua Hai Yu
Keyword(s):  
Mechanical Properties ◽  
Cyclic Load ◽  
Room Temperature ◽  
Chemical Vapor ◽  
Cyclic Fatigue ◽  
Fatigue Tests ◽  
Carbon Cloth ◽  
Bending Tests ◽  
Three Point Bending ◽  
Properties Of Composites

Bending cyclic fatigue tests of 2D laminated C/C composites were conducted under load control at a sinusoidal frequency of 10 Hz. And three-point bending tests of fatigued specimens with various cycles were conducted at room temperature to evaluate the effects of cyclic load on mechanical properties. 2D C/C specimens were prepared by an isothermal chemical vapor deposition (CVD) process. The mechanical properties of composites were improved after cyclic loading at most the flexural strength by about 46% and the modulus 38%. The results show that the flexural properties of C/C composites were enhanced with the increase in fatigue cycles. It is suggested that the weakened interface between matrix and fibers by cyclic load play important roles in enhancing the property of C/C composites.

scholarly journals On the Evaluation of the Mechanical Behaviour of Structural Glass Elements

2006 ◽  
Vol 514-516 ◽  
pp. 799-803 ◽  
Author(s):  
Sandra Costa ◽  
Micaela Miranda ◽  
Humberto Varum ◽  
Filipe Teixeira Dias
Keyword(s):  
Mechanical Behaviour ◽  
State Of The Art ◽  
Building Construction ◽  
Structural Glass ◽  
Tempered Glass ◽  
Structural Element ◽  
Bending Tests ◽  
Three Point Bending ◽  
Structural Applications ◽  
Strength And Stiffness

Glass can be considered to be a high-technology engineering material with a multifunctional potential for structural applications. However, the conventional approach to the use of glass is often based only on its properties of transparency and isolation. It is thus highly appropriate and necessary to study the mechanical behaviour of this material and to develop adequate methods and models leading to its characterisation. It is evident that the great potential of growth for structural glass applications is an important opportunity of development for the glass industry and the building/construction sectors. The work presented in this paper is a reflection of this conclusion. The authors shortly present the state-of-the-art on the application of glass as a structural element in building and construction, and refer to other potential fields of application and available glass materials. The experimental procedures and methods adopted in three-point bending tests performed on 500 × 100 [mm2] float, laminated and tempered glass specimens with thicknesses between 4 and 19 mm are thoroughly described. The authors evaluated the mechanical strength and stiffness of glass for structural applications. This work contributes to a deeper knowledge of the properties of this material.

Failure of an Advanced Five Layers RT800 Composite

2015 ◽  
Vol 760 ◽  
pp. 299-304
Author(s):  
Vasile Gheorghe ◽  
Florin Teodorescu-Draghicescu ◽  
Dora Raluca Ionescu
Keyword(s):  
Mechanical Properties ◽  
Glass Fibers ◽  
Testing Machine ◽  
Experimental Tests ◽  
Specific Weight ◽  
Materials Testing ◽  
Bending Tests ◽  
Three Point Bending ◽  
Median Part ◽  
Glass Mat

This paper presents mechanical properties of five layers RT800 glass mat laminate impregnated with polyester resin and subjected to three-point bending tests until break. The RT800 glass mat used as reinforcement presents randomly disposed short glass fibers with 845 g/m2specific weight. From the cured plate, twenty specimens have been cut and placed on a three-point bending device and tested using a materials testing machine with servo hydraulic command. The specimens have been carried out at Compozite Ltd Brasov and the experimental tests have been accomplished at SC INAR SA Brasov and Transilvania University of Brasov. Outstanding mechanical properties of this kind of material have been found in which the specimens have suffered delamination mainly in their median part.

Investigation of The Elastic Modulus of Sol-Gel Derived Titania Using Three-Point Bending Tests

1996 ◽  
Vol 436 ◽  
Author(s):  
Å. K. Jämting ◽  
J. M. Bell ◽  
M. V. Swain
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Sol Gel ◽  
Bending Tests ◽  
Three Point Bending ◽  
Compositional Uniformity ◽  
Titania Films ◽  
Sol Gel Films ◽  
Film Porosity ◽  
Thickness Measurements

AbstractThere is increasing interest in the use of sol-gel derived films in tribological applications, and this necessitates an understanding of the mechanical properties of these films. Few investigations into the mechanical properties of sol-gel films have been undertaken, and in this study we have concentrated on measurement of the elastic modulus of sol-gel derived titania films as a preliminary stage in a full investigation of stress in sol-gel deposited thin films. Sol-gel films are often very thin and in order to understand the influence of the substrate on the measured elastic modulus, we have used a multiple coating technique to deposit titania films of increasing thickness on various substrates. A three point bending apparatus is used to measure the elastic modulus. The three-point bending apparatus has very low load and displacement measuring capabilities as is required for the very thin sol-gel films. Measurements of the compositional uniformity of the films have been performed using RBS, and this has been combined with film thickness measurements to determine the film porosity. This information ensures that the measured properties relate to intrinsic film properties. The results of all these measurements will be presented.

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