INTRODUCTION The purpose of this study was to evaluate the effect of various degrees of cyclic fatigue on torsional failure and torsional preloading on the cyclic fatigue life of heat-treated K3XF nickel-titanium (NiTi) instruments (SybronEndo, Orange, CA). METHODS The mean number of cycles until failure (Nf) of K3XF and K3 NiTi instruments was examined in a 3-point bending apparatus with a 7...

A series of wind tunnel model tests and theoretical analyses were conducted to investigate torsion excitation, response and vibration suppression of wind-excited buildings. An aeroelastic model for pure torsion vibration was developed and the aeroelastic test results were compared with those obtained by other Wind tunnel test techniques. The comparison and practice indicated that this type of m...

Dear Editor-in-Chief, I am writing as an engineer and orthopaedic surgeon to express a few concerns about methodology for mechanical testing appearing in your journal over the years. The latest example is that by Hutcheson, et al., “Comparison of double locking plate constructs with single non-locking plate constructs in single cycle to failure in bending and torsion”, that appeared in VCOT iss...

Tests of the lateral and torsional stability are quite sensitive to the experimental conditions, such as support conditions and loading system. Controlling all of these conditions in a full-size test is a very challenging task. Therefore, in this paper, an experimental measurement method that can control the experimental conditions using a small-scale model was proposed to evaluate the lateral ...

Accurate prediction of the torsional barrier height in tolane is achieved by systematically extrapolating to the Dunning complete basis set limit at MP2 level with a spin-component-scaled correction. The zero-point energy correction is calculated at the B98/cc-pVDZ level based on a benchmark test using the experimental data for benzene. The final calculated barrier height is 202.2 cm, in excell...

the cadaver spine motion segment behavior under torsional load was evaluated with the disc intact, with partial anterior discectomy and with spacer insertion. the results of this study explain how anterior lumbar discectomy and interbody fusion (alif) affects the torsional stability of the motion segment. the pseudarthrosis rate of the anterior lumbar discectomy and interbody fusion (alif) is k...

A B S T R A C T Pump shafts used for power generation are susceptible to fatigue cracking while often in near-continuous operation. Technology based on torsional vibration is under development for condition-based assessment of shaft health. The focus of this paper is on the relationship between a crack, which propagated due to bending loads, and the torsional stiffness of the shaft. An analytic...

Two types of prime movers are continuously applied for rotating machinery: mechanical and electric drives. This tutorial focuses on electric drives, which are actually composed of separate components: electric motor, frequency converter (optional), and electric network including transformers. The main aim of this tutorial is to explain the phenomena of electric drives related to the torsional v...

During earthquake excitations, reinforced concrete bridge columns can be subjected to a combination of axial load, shear force, flexural moments, and torsional moments. The torsional moment can be much more significant in columns of bridges that are skewed, curved, have unequal spans, or unequal column heights. Combined loading including torsion can result in complex flexural and shear failure ...

Wet friction clutches play a critical role in vehicles equipped with automatic transmissions. It is unavoidable that they progressively degrade and eventually break down while the vehicles are under operational condition. To avoid unexpected failures, a proper condition monitoring tool extended with a lifetime prediction method should be implemented. In order to achieve this, appropriate parame...