Evaluation of Non-uniformity of Specimen During Hollow Torsional Test

This paper presents torsional test results for six ductile metals subjected to large shear strains and high strain rates. Included are OFHC copper, Cartridge brass, Nickel 200, Armco IF iron, Carpenter electrical iron, and 1006 steel. Torsional shear strains as high as 700 percent are achieved and strain rates vary from quasi-static to over 300 s−1. At the lower strain rates all of the materials exhibit positive strain hardening and strain rate hardening under essentially isothermal conditions. At the higher strain rates there is significant adiabatic thermal softening and strong evidence for shear instabilities and localizations. Constitutive relationships are derived from the test data and finite element computations of the tests are performed.

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Torsional test

Encyclopedic Dictionary of Polymers ◽

10.1007/978-0-387-30160-0_11734 ◽

2007 ◽

pp. 988-988

Keyword(s):

Torsional Test

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Examination of Bone Like Materials

Materials Science Forum ◽

10.4028/www.scientific.net/msf.812.233 ◽

2015 ◽

Vol 812 ◽

pp. 233-238

Author(s):

Dávid Pammer ◽

Eszter Bognár

Keyword(s):

Structural Properties ◽

Surgical Techniques ◽

Healing Time ◽

Geometrical Parameters ◽

Insertion Torque ◽

Bone Modeling ◽

Implant Stability ◽

Mechanical And Structural Properties ◽

Torsional Test ◽

The Ideal

The aim of this research is to develop a new minimally invasive measurement procedure. With this method implantologist could determine the local mechanical and structural properties of the cellular solids materials (e.g. bones) into which implants are placed. The currently applied methods are based on image measurement procedures (CT, Hounsfield scale etc.). The dentists, with the knowledge of the determined mechanical properties of the bone, can choose the ideal surgical parameters (flap size, diameter of drill, hole-depth, healing time, etc.) and the ideal implant type for the patients. During the development of the measuring procedure, was used bone modeling materials (“bone-like materials”) instead of bone. With these materials it is easier to do tests, than with living tissues. The bone like materials needs to have the same mechanical and structural properties as the given bone. The following bone like materials was used during the measurement: woods (Amaranth, Alnus, Ipe, Iroko, Robinia, Pyrus, Zebrano), and on the market available polyurethane solid foams (Sawbones D1 and D2). Among the literatures are summaries, which include the biomechanical assessments for implant stability. These technics are good to determine the implant stability in different bones and bone like materials after the implantation. In this work torsional test were used. This test is based on the determination of the insertion torque as a function of the implant displacement. Used the insertion torque functions and the screw geometrical parameters, the rotational work was determined. The different materials insertion torque functions have different slope values. The slopes and the rotational work results show which bone like material has similar insertion parameters (insertion torque function, rotational work) as a mandible during the insertion of an implant. With this torsional test and the knowledge of the bone like materials insertion torque functions and the rotational works it is possible to find the best material for the modeling of an implantation. Using this material, medical students can practice and improved the surgical techniques.

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Influence of Different Heat Treatments on Torsional and Cyclic Fatigue Resistance of Nickel–Titanium Rotary Files: A Comparative Study

Applied Sciences ◽

10.3390/app10165604 ◽

2020 ◽

Vol 10 (16) ◽

pp. 5604 ◽

Cited By ~ 2

Author(s):

Gianluca Gambarini ◽

Andrea Cicconetti ◽

Dario Di Nardo ◽

Gabriele Miccoli ◽

Alessio Zanza ◽

...

Keyword(s):

Heat Treatment ◽

Fatigue Resistance ◽

Cyclic Fatigue ◽

Sem Analysis ◽

Nickel Titanium ◽

Torsional Resistance ◽

Heat Treated ◽

Torsional Test ◽

Time To Fracture ◽

Flexural Resistance

Protaper Universal (PTU), Protaper Gold (PTG) (Maillefer, Ballaigues, CH), EdgeTaper (ET), and EdgeTaper Platinum (ETP) (Albuquerque, NM, USA) were tested for both torsional and flexural resistance. The aim of the present study was to evaluate the influence of proprietary heat treatment on the metallurgical properties of the aforementioned instruments. Four groups of 30 different instruments (size 20.07) were tested, then divided into two subgroups of 15 instruments—one for the cyclic fatigue test in a curved canal (90°—2 mm radius) at 300 rpm and 2.5 Ncm. The time to fracture (TtF) and fragment length (FL) were recorded. The other subgroup was subjected to the torsional test (300 rpm, 5.5 Ncm). The torque to fracture and TtF were recorded. All the instruments underwent a SEM analysis. The heat-treated instruments showed a significantly higher fatigue resistance than the non-heat-treated instruments (p < 0.05). No significant differences were found in the torsional resistance between the ET and PTU, and the ETP and PTG. However, when comparing all the groups, the heat-treated instruments showed less torsional resistance. The improvement from heat treatment was mainly found in the cyclic fatigue resistance.

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A Study of Mode III Fracture Toughness in Young and Mature Concrete with Fly Ash Additive

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.254.120 ◽

2016 ◽

Vol 254 ◽

pp. 120-125 ◽

Cited By ~ 18

Author(s):

Grzegorz Ludwik Golewski ◽

Tomasz Sadowski

Keyword(s):

Fracture Toughness ◽

Fly Ash ◽

Fracture Mechanics ◽

Test System ◽

Special Device ◽

Mode Iii ◽

Concrete Mixtures ◽

Young Concrete ◽

Torsional Test ◽

Class F Fly Ash

A description of processes of formation and propagation of cracks in material requires the knowledge of all fracture mechanics parameters, i.e.: KIc, KIIcand KIIIc. In this study a new testing method and estimation of the fracture toughness in Mode III (antiplane shear) of concretes containing: 0, 20 and 30% volume content of the class F fly ash (FA) was proposed. Fracture toughness tests were performed on axial torsion machine MTS 809 Axial/Torsional Test System. The studies examined effect of FA additive on the parameter KIIIc. In order to determine the fracture toughness KIIIca special device was made. Experimental investigation under third mode fracture was carried out both in young and mature concrete composites (after: 3, 7, 28, 90, 180 and 365 days). 20% addition of FA as well as a 30% addition of FA causes a reduction in fracture toughness of young concrete. After 28 days of couring a significant increase of the KIIIc was noticed in composites with a 20% additive of FA while concrete mixtures with a higher additive of FA still had lower analyzed fracture mechanics parameter.

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Space Frame Analysis, Design, and Testing for Electric Vehicle Formula

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.619.183 ◽

2014 ◽

Vol 619 ◽

pp. 183-187 ◽

Cited By ~ 1

Author(s):

Thanyarat Singhanart ◽

Thammongkol Sangmanacharoen ◽

Wasin Tocharoen ◽

Phongpakkan Danwibun

Keyword(s):

Electric Vehicle ◽

Torsional Stiffness ◽

Steel Tubes ◽

Space Frame ◽

Element Analysis ◽

Electric Car ◽

Torsional Test ◽

Analysis Design ◽

Design And Testing ◽

Engine Type

The objective of this paper is to design, analyze, and test the space frame for electric vehicle with comparison to the engine type. Therefore, in order to design the electric vehicle formula, the same requirements with some changes are considered. The space frame is designed to suit with the electric vehicle and then finite element analysis is used to determine the torsional stiffness of the frame which is verified by the torsional test. Initially, the required torsional stiffness for the electric car is 1350 Nm/deg and the mass is set to be not more than 40 kg. The numerical results and the experimental results for torsional stiffness are 960 Nm/deg and 1218 Nm/deg, respectively. Therefore, the torsional stiffness is about 25% under-predicted; anyway it can be used to predict the torsional stiffness of the frame. Due to some changes must be performed, therefore the modified frame is re-analyzed with the torsional stiffness of 1389 Nm/deg which is less than the revised required car’s torsional stiffness of 1404 Nm/deg. Anyway, the torsional stiffness of frame with battery’s case can meet the requirement. The mass of the modified frame is 50 kg which is larger than required mass due to selected sizes of steel tubes. In conclusion, the space frame can be designed and the mass can be improved further by reducing the sizes.

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