Determination of Local Tensile and Fatigue Properties With the Use of Sub-Sized Specimens

Determination of mechanical properties with the use of sub-sized specimens is very important topic nowadays. The use of sub-sized samples can be quite wide in all cases when limited amount of the experimental material is available such as evaluation of residual life of in-service components, properties determination of developed nano-structured materials, assessment of dilatometric samples used for thermal and thermo-mechanical treatment development, local properties of weld joints and so on. Concerning this large application field it would be very useful to prepare standard for small size samples especially for most demanded material properties: tensile properties, notch impact transition temperature, fatigue properties, fracture toughness and creep. One of the widely used methods of miniature sample testing is Small Punch Test (SPT) that is used for determination of all above mentioned properties. However the main drawback of this method is need of known correlation relation between considered property and SPT for the material of interest. The correlation is needed due to different loading mode in comparison between SPT and standard test methods. Unfortunately, transferability of these correlation parameters between labs is very limited and thus each lab has to determine its own that limits the use of this method. More interest is recently paid to development of small size samples procedures using miniaturized standardized samples maintaining big advantage — the same loading mode between small sized and full sized samples. The same loading mode significantly reduces or completely removes complexity of the results transfer from small to standard size samples. The current paper is dealing with overview of various applications of small sized tensile tests and fatigue tests. Concerning tensile tests quasi static tensile test at room temperature as well as at elevated temperature are show together with results of dynamic tests and special tests of metastable supercooled austenite. The developed procedures performance is demonstrated by comparison of standard size and sub-size specimens results comparison for all tests, except supercooled austenite tests, where no standard size specimen exists.

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Low Cycle Fatigue Tests With the Use of Miniaturized Test Specimens

Volume 1A: Codes and Standards ◽

10.1115/pvp2017-66174 ◽

2017 ◽

Cited By ~ 1

Author(s):

Jan Dzugan ◽

Radek Prochazka ◽

Pavel Konopik

Keyword(s):

Residual Life ◽

Low Cycle Fatigue ◽

Fem Analysis ◽

Fatigue Tests ◽

Fatigue Properties ◽

Treatment Development ◽

Structured Materials ◽

Testing Procedures ◽

Large Application

Determination of mechanical properties with the use of sub-sized specimens is topic a high interest nowadays. The application of the sub-sized samples is quite wide for all cases where only limited amount of the experimental material is available such as evaluation of additively manufactured products properties, residual life of in-service components, properties determination of developed nano-structured materials, assessment of dilatometric samples used for thermal and thermo-mechanical treatment development, local properties of components, weld joints and so on. Concerning this large application field it would be very useful to prepare standard for small size samples especially for the most demanded material properties: tensile properties, notch impact transition temperature, fatigue properties, fracture toughness and creep. Current paper is going to deal with the low fatigue (LCF) properties assessment with the use of miniaturized specimens’. There were proposed specimen geometries with the use of FEM analysis and testing procedures for considered mini-specimens tests were developed. In the case of strain controlled LCF tests, contactless testing system had to be established for testing of small sized specimens, where it is not possible to apply standard mechanical extensometers for test control. Moreover, LCF procedure for high temperature tests was also successfully established here. The LCF results were subsequently used for Manson-Coffin parameters determination. Results of low cycle tests for several steels are confronted with the results of standard sized specimens with very good agreement for all considered conditions.

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Analisis Pengaruh Temperatur Pemanasan Terhadap Sifat Fisis Sinter Silika dan Tipe Fluida (Air) pada Mata Air Panas Sapan Maluluang, Kecamatan Alam Pauh Duo, Kabupaten Solok Selatan

Jurnal Fisika Unand ◽

10.25077/jfu.6.1.1-8.2017 ◽

2017 ◽

Vol 6 (1) ◽

pp. 1-8

Author(s):

Tania Dian Putri ◽

Ardian Putra

Keyword(s):

Test Methods ◽

Standard Test ◽

Laboratory Determination

Telah dilakukan analisis sifat fisis sinter silika dan tipe fluida pada mata air panas Sapan Maluluang Kecamatan Alam Pauh Duo, Solok Selatan. Sifat fisis yang diteliti dalam penelitian ini yaitu densitas dengan menggunakan hukum Archimedes, porositas dengan menggunakan standar ASTM D7263-09 (Standard Test Methods for Laboratory Determination of Density of Soil Specimens), dan resistivitas dengan metode Probe Dua Elektroda. Nilai densitas, porositas dan resistivitas sinter silika pada temperatur 31oC dalam pengukuran ini adalah 1,206 g/cm3, 15,8 %, dan 7,195 Ωm. Pengaruh temperatur terhadap sifat fisis sinter silika juga dianalisis dalam penelitian ini. Berdasarkan pengukuran, peningkatan temperatur dari 175 oC hingga 300 oC mengakibatkan nilai densitas turun dari 1,112 g/cm3 menjadi 0,983 g/cm3, sedangkan nilai porositas sinter silika naik dari 33,3 % menjadi 53,3 %. Nilai resistivitas sinter silika juga mengalami peningkatan dari 23,035 Ωm menjadi 57,201 Ωm. Terdapat hubungan nilai faktor resistivitas dengan porositas yaitu bertambahnya pori-pori sinter silika mengakibatkan nilai faktor resistivitas mengecil. Hubungan nilai faktor resistivitas dan porositas sinter silika menghasilkan nilai sementasi dan tortuositas sinter silika. Meningkatnya temperatur sinter silika dari 175 oC hingga 300 oC menyebabkan nilai tortuositas meningkat dari 6,92 menjadi 48,89 dan sementasi mengecil dari 1,67 menjadi 1,08. Penentuan tipe fluida mata air panas, menggunakan kandungan sulfat, klorida dan bikarbonat yang terdapat pada air panas. Metode yang digunakan dalam pengujian kandungan sulfat yaitu Spektrofotometri, sedangkan kandungan klorida dan bikarbonat diuji dengan metode Argentometri cara Mohr dan metode titrasi asam basa. Berdasarkan pengolahan data menggunakan diagram trilinier, mata air panas Sapan Maluluang termasuk kedalam tipe air panas klorida karena kandungan klorida merupakan kandungan yang paling dominan yaitu mencapai 97,560 mg/L, sedangkan kandungan sulfat dan bikarbonat mencapai 21,333 mg/L dan 23,730 mg/L. Kata kunci : densitas, porositas, resistivitas, sinter silika, tipe air panas

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Fatigue Properties of 3D Welded Thin Structures

Volume 12: Mechanics of Solids, Structures, and Fluids ◽

10.1115/imece2020-23135 ◽

2020 ◽

Author(s):

Seyed M. Allameh ◽

Avery Lenihan ◽

Roger Miller ◽

Hadi Allameh

Keyword(s):

Mechanical Properties ◽

3D Printing ◽

Fatigue Testing ◽

Interfacial Area ◽

Tensile Tests ◽

Orientation Dependence ◽

Fatigue Tests ◽

Fatigue Properties ◽

Mig Welding ◽

Welded Structures

Abstract Additive manufacturing technology has matured enough to produce real industrial components. A newer method of 3D printing is the deposition of molten metal beads using a MIG weld torch. This involves a 3D printer equipped with a MIG torch layering the metals in desired shapes. It allows the fabrication of components made of MIG weld wires, currently available from various elements including Cu, Al, steel and alloys. Some of these structures made by 3D welding will have applications in critical load bearing conditions. The reliability of such components will be vital in applications where human lives are at stake. Tensile tests are conducted to verify the required strength of the fabricated parts which will undergo monotonic loading; however, fatigue tests are required for cases where cyclic loading will take place. Conventional tensile and fatigue testing requires macro-scale samples. With MIG welding, it is possible to make thin-walled structures. Fatigue testing on samples extracted from thin walls is made possible by microtesting. This study is focused on the mechanical properties of 3D welded structures made from MIG welding wires. Our earlier results showed orientation dependence of mechanical properties in 3D welded structures. They also showed the effect of substrates in expression of the orientation dependence. Welding on metal substrate produces weld beads that are harder at the substrate interfacial area. However, for structures welded on ceramics, the opposite is true. They exhibit a softer substrate interfacial area and a relatively harder top. Our newer results show fatigue properties of structures made by 3D welding. Microsamples measuring 0.2 mm × 0.2 mm × 1.0 mm were extracted from metal beads using a CNC mill along with an EDM. The contours of the samples were machined by milling and the back side was cut by electro discharge machining. Specimens were then polished to the desired size and mounted in the grippers of an E1000 Instron load frame. WaveMatrix® application software from Instron was used to control the machine and to obtain testing data. Fatigue tests were performed, and life cycles were determined for various stress levels up to over 5 million cycles. The preliminary results of tensile tests of these samples show strength levels that are comparable to those of parent metal, in the range of 600–950MPa. Results of fatigue tests show high fatigue lives associated with relatively high stresses. The preliminary results will be presented and the implications of the use of 3D welded rebar in 3D printing of reinforced concrete structures will be discussed.

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Standard Test Methods for the Determination of VOCs and SVOCs in Automobile Interiors

Organic Indoor Air Pollutants ◽

10.1002/9783527628889.ch7 ◽

2009 ◽

pp. 147-164

Author(s):

Michael Wensing

Keyword(s):

Test Methods ◽

Standard Test

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Determination of the Residual Life of the Spraying Boom of a Field Sprinkler in the Maneuvering Loading Mode

Materials Science ◽

10.1007/s11003-020-00404-2 ◽

2020 ◽

Vol 56 (1) ◽

pp. 112-118

Author(s):

O. E. Andreikiv ◽

A. V. Babii ◽

I. Ya. Dolinska ◽

Yu. Ya. Matviiv

Keyword(s):

Residual Life ◽

Loading Mode

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Fatigue Properties of Al-Li Plates Joined by Friction Stir Welding

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.385-387.849 ◽

2008 ◽

Vol 385-387 ◽

pp. 849-852 ◽

Cited By ~ 1

Author(s):

Pasquale Cavaliere ◽

Francesco W. Panella ◽

Antonio Squillace

Keyword(s):

Mechanical Properties ◽

Cross Sections ◽

Testing Machine ◽

Rolling Direction ◽

Tensile Tests ◽

Fatigue Tests ◽

Control Mode ◽

Fatigue Properties ◽

Amplitude Control ◽

Friction Stir

Al-Li alloys are characterized by a strong anisotropy in mechanical properties and microstructure with respect to the rolling direction. Plates of 2198 Al-Li alloy were friction stir welded by employing maximum rotation speed: 1000 rev/min and welding speed of 80 mm/min, both in parallel and orthogonal directions with respect to the rolling one. The joints mechanical properties were evaluated by means of tensile tests at room temperature. In addition, fatigue tests performed with a resonant electro-mechanical testing machine under constant amplitude control up to 250 Hz loading, were conducted in axial control mode with R(σmin/σmax)=0.33, for all the welding and rotating speed conditions. The fatigue crack propagation experiments were performed by employing single edge notched specimens.With the aim to characterize the weld performances, both the microstructure evolution at jointed cross sections, related to the welding variables, and the fractured surfaces were respectively analyzed by means of optical and scanning electron microscopy.

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Effect of Thermal Exposure on Tensile and Fatigue Properties of Clay Reinforced Nylon Nanocomposites

Materials Science Forum ◽

10.4028/www.scientific.net/msf.833.52 ◽

2015 ◽

Vol 833 ◽

pp. 52-55

Author(s):

Yukiko Nakahara ◽

Yusuke Kodama ◽

Shi Jie Zhu ◽

Arimitsu Usuki ◽

Makoto Kato

Keyword(s):

Tensile Strength ◽

Room Temperature ◽

Thermal Exposure ◽

Tensile Tests ◽

Nylon 6 ◽

Fatigue Tests ◽

Fatigue Properties ◽

Oxidation Treatment ◽

Exposure Temperature ◽

Matrix Nanocomposite

In this paper, both nylon 6 and 2 wt% clay reinforced nylon 6 matrix nanocomposite were used for thermal exposure tests at temperatures of 80 oC and 120 oC and 150 oC, respectively. Then, the tensile tests and fatigue tests of the exposed specimens were conducted at room temperature. It was shown that the tensile strength in both nylon 6 and NCH-2 decreased with an increase in thermal exposure temperature. The brittle fracture occurred in the specimens exposed at 120 oC and 150 oC. After pre-oxidation treatment at 80 °C for 100 hours, the fatigue strength decreased 14% in nylon 6, and 8% in NCH-2. From this result, it was understood that the addition of clay in nylon 6 could suppress the decrease of fatigue strengths.

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