Monitoring Acoustic Emissions from Finger-Joints from Tropical African Hardwoods for Predicting Ultimate Tensile Strength

Holzforschung ◽  
2001 ◽  
Vol 55 (6) ◽  
pp. 652-660
Author(s):  
J. Ayarkwa ◽  
Y. Hirashima ◽  
K. Ando ◽  
Y. Sasaki
Keyword(s):  
Tensile Strength ◽  
Acoustic Emission ◽  
Ultimate Tensile Strength ◽  
Acoustic Emissions ◽  
Tension Test ◽  
Regression Coefficients ◽  
Finger Joints ◽  
Acoustic Emission Count ◽  
Monitoring Procedure ◽  
Species Type

Summary The patterns of acoustic emissions generated during tension test of finger-joints from three tropical African hardwoods, Obeche (Triplochiton scleroxylon), Makore (Tieghemella heckelii) and Moabi (Baillonella toxisperma) were evaluated to assess their potential usefulness for non-destructively predicting ultimate tensile strength. The acoustic emission patterns generated were observed to differ depending on the type of finger profile and the wood species. Regression coefficients from cumulative acoustic emission count versus applied stress squared functions also varied with the profile and species type. When ultimate tensile strength was correlated with these regression coefficients, for stresses applied up to 50% of mean ultimate strength, the logarithmic regression model developed could predict finger-joint strength accurate to ±12%, ±13% and ±18% for Obeche, Makore and Moabi, respectively. The model was also sensitive to the type of finger profile used for all three tropical African hardwoods. The results indicate that this acoustic emission monitoring procedure could be useful for non-destructively predicting ultimate tensile strength of finger-joints from the three tropical African hardwoods.

Artificial Neural Network Prediction of Ultimate Tensile Strength of Randomly Oriented Short Glass Fibre-Epoxy Composite Specimen using Acoustic Emission Parameters

2015 ◽  
Vol 24 (5) ◽  
pp. 096369351502400 ◽  
Author(s):  
S. Ramkumar
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Tensile Strength ◽  
Acoustic Emission ◽  
Ultimate Tensile Strength ◽  
Glass Fibre ◽  
Testing Machine ◽  
Cumulative Energy ◽  
Feed Forward Back Propagation ◽  
Artificial Neural

Acoustic emission (AE) data have been collected from 20 randomly oriented short E-glass fibre – unsaturated polyester tensile specimens, while loading up to failure in a tensile testing machine. Peak amplitude and cumulative energy data from AE response of each specimen were classified and segregated by understanding the failure mechanism and data acquired up to 50% of the failure load was utilized for analysis. An optimized feed-forward back-propagation (FFBP) type artificial neural network (ANN) was designed and the segregated data of amplitude hits and cumulative energy was processed using it. Even though the accuracy of both networks were satisfactory, amplitude hit based network gave better predictions of the ultimate tensile strength (UTS) than the energy based network. Also the performance of various training algorithms in the designed network was analysed and the results were compared.

Wear Process Description Based on Acoustic Emission

1990 ◽  
Vol 112 (3) ◽  
pp. 469-476 ◽  
Author(s):  
B. E. Klamecki ◽  
J. Hanchi
Keyword(s):  
Acoustic Emission ◽  
Wear Behavior ◽  
Acoustic Emissions ◽  
Amplitude Distribution ◽  
Wear Process ◽  
Acoustic Emission Count ◽  
Deformation And Fracture ◽  
Emission Activity ◽  
Active Processes ◽  
Insight Into

Since acoustic emissions are generated by fundamental mechanical processes, they can provide insight into the basic processes which determine friction and wear behavior. Descriptions of acoustic emission generated by plastic deformation and fracture were developed, and wear tests were performed, during which acoustic emission activity was measured. This work demonstrates that acoustic emissions can be used to track the wear process in terms of the energy dissipation mechanisms acting. The results show that acoustic emission count rate and amplitude distribution correspond to wear rate and that the amplitude distribution also indicates the active processes contributing to wear.

An appraisal of characteristic mechanical properties and microstructure of friction stir welding for Aluminium 6061 alloy – Silicon Carbide (SiCp) metal matrix composite

2019 ◽  
Vol 13 (4) ◽  
pp. 5804-5817
Author(s):  
Ibrahim Sabry
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Metal Matrix ◽  
Welded Joint ◽  
Rotation Speed ◽  
Fusion Welding ◽  
Friction Stir ◽  
Al 6061

It is expected that the demand for Metal Matrix Composite (MMCs) will increase in these applications in the aerospace and automotive industries sectors, strengthened AMC has different advantages over monolithic aluminium alloy as it has characteristics between matrix metal and reinforcement particles.  However, adequate joining technique, which is important for structural materials, has not been established for (MMCs) yet. Conventional fusion welding is difficult because of the irregular redistribution or reinforcement particles.  Also, the reaction between reinforcement particles and aluminium matrix as weld defects such as porosity in the fusion zone make fusion welding more difficult. The aim of this work was to show friction stir welding (FSW) feasibility for entering Al 6061/5 to Al 6061/18 wt. % SiCp composites has been produced by using stir casting technique. SiCp is added as reinforcement in to Aluminium alloy (Al 6061) for preparing metal matrix composite. This method is less expensive and very effective. Different rotational speeds,1000 and 1800 rpm and traverse speed 10 mm \ min was examined. Specimen composite plates having thick 10 mm were FS welded successfully. A high-speed steel (HSS) cylindrical instrument with conical pin form was used for FSW. The outcome revealed that the ultimate tensile strength of the welded joint (Al 6061/18 wt. %) was 195 MPa at rotation speed 1800 rpm, the outcome revealed that the ultimate tensile strength of the welded joint (Al 6061/18 wt.%) was 165 MPa at rotation speed 1000 rpm, that was very near to the composite matrix as-cast strength. The research of microstructure showed the reason for increased joint strength and microhardness. The microstructural study showed the reason (4 %) for higher joint strength and microhardness.  due to Significant   of SiCp close to the boundary of the dynamically recrystallized and thermo mechanically affected zone (TMAZ) was observed through rotation speed 1800 rpm. The friction stir welded ultimate tensile strength Decreases as the volume fraction increases of SiCp (18 wt.%).

VASCO 9-4-20

Alloy Digest ◽  
1997 ◽  
Vol 46 (10) ◽  
Keyword(s):  
Fracture Toughness ◽  
Tensile Strength ◽  
High Temperature ◽  
Ultimate Tensile Strength ◽  
Physical Properties ◽  
Tensile Properties ◽  
Heat Treating ◽  
High Tensile Strength ◽  
Temperature Performance

Abstract Vasco 9-4-20 (0.20 wt% C) is a premium quality aircraft steel that combines high tensile strength with good fracture toughness. It is a heat-treatable alloy capable of developing an ultimate tensile strength greater than 190 ksi. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance as well as heat treating, machining, and joining. Filing Code: SA-489. Producer or source: Vasco, An Allegheny Teledyne Company.

Vibratory weld conditioning during gas tungsten arc welding of al 5052 alloy on the mechanical and micro-structural behavior

2020 ◽  
Vol 17 (6) ◽  
pp. 831-836
Author(s):  
M. Vykunta Rao ◽  
Srinivasa Rao P. ◽  
B. Surendra Babu
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Welded Joints ◽  
Great Influence ◽  
Welding Process ◽  
Microstructural Characterization ◽  
Content Type ◽  
Average Grain Size

Purpose Vibratory weld conditioning parameters have a great influence on the improvement of mechanical properties of weld connections. The purpose of this paper is to understand the influence of vibratory weld conditioning on the mechanical and microstructural characterization of aluminum 5052 alloy weldments. An attempt is made to understand the effect of the vibratory tungsten inert gas (TIG) welding process parameters on the hardness, ultimate tensile strength and microstructure of Al 5052-H32 alloy weldments. Design/methodology/approach Aluminum 5052 H32 specimens are welded at different combinations of vibromotor voltage inputs and time of vibrations. Voltage input is varied from 50 to 230 V at an interval of 10 V. At each voltage input to the vibromotor, there are three levels of time of vibration, i.e. 80, 90 and 100 s. The vibratory TIG-welded specimens are tested for their mechanical and microstructural properties. Findings The results indicate that the mechanical properties of aluminum alloy weld connections improved by increasing voltage input up to 160 V. Also, it has been observed that by increasing vibromotor voltage input beyond 160 V, mechanical properties were reduced significantly. It is also found that vibration time has less influence on the mechanical properties of weld connections. Improvement in hardness and ultimate tensile strength of vibratory welded joints is 16 and 14%, respectively, when compared without vibration, i.e. normal weld conditions. Average grain size is measured as per ASTM E 112–96. Average grain size is in the case of 0, 120, 160 and 230 is 20.709, 17.99, 16.57 and 20.8086 µm, respectively. Originality/value Novel vibratory TIG welded joints are prepared. Mechanical and micro-structural properties are tested.

scholarly journals Effects of Substitution of Y with Yb and Ce on the Microstructures and Mechanical Properties of Mg88.5Zn5Y6.5

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 31
Author(s):  
Hongxin Liao ◽  
Taekyung Lee ◽  
Jiangfeng Song ◽  
Jonghyun Kim ◽  
Fusheng Pan
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Creep Resistance ◽  
Room Temperature ◽  
High Thermal Stability ◽  
Long Period ◽  
Microstructures And Mechanical Properties

The microstructures and mechanical properties of the Mg88.5Zn5Y6.5-XREX (RE = Yb and Ce, X = 0, 1.5, 3.0, and 4.5) (wt.%) alloys were investigated in the present study. Mg88.5Zn5Y6.5 is composed of three phases, namely, α-Mg, long-period stacking ordered (LPSO) phases, and intermetallic compounds. The content of the LPSO phases decreased with the addition of Ce and Yb, and no LPSO phases were detected in Mg88.5Zn5Y2.0Yb4.5. The alloys containing the LPSO phases possessed a stratified microstructure and exhibited excellent mechanical properties. Mg88.5Zn5Y5.0Ce1.5 exhibited the highest creep resistance and mechanical strength at both room temperature and 200 °C, owing to its suitable microstructure and high thermal stability. The yield strength of Mg88.5Zn5Y5.0Ce1.5 at room temperature was 358 MPa. The ultimate tensile strength of Mg88.5Zn5Y5.0Ce1.5 at room temperature and 200 °C was 453 MPa and 360 MPa, respectively.

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