Experimental investigation of T-tubular joint subjected to complex loading conditions

2001 ◽  
Author(s):  
S. T. Lie ◽  
S. P. Chiew ◽  
S. Sun
Keyword(s):  
Experimental Investigation ◽  
Complex Loading ◽  
Loading Conditions ◽  
Tubular Joint

Experimental investigation on the web crippling behaviour of pultruded GFRP wide-flange sections subjected to two-flange loading conditions

2021 ◽  
Vol 259 ◽  
pp. 113469 ◽  
Author(s):  
Jyotirmoy Haloi ◽  
Suman Kumar Mushahary ◽  
Arun Chandra Borsaikia ◽  
Konjengbam Darunkumar Singh
Keyword(s):  
Experimental Investigation ◽  
Loading Conditions ◽  
Web Crippling ◽  
The Web

Effects of Surface Finish and Loading Conditions on the Low Cycle Fatigue Behavior of Austenitic Stainless Steel in PWR Environment for Various Strain Amplitude Levels

2009 ◽  
Author(s):  
Jean Alain Le Duff ◽  
Andre´ Lefranc¸ois ◽  
Jean Philippe Vernot
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Strain Amplitude ◽  
Surface Finish ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Complex Loading ◽  
Loading Conditions ◽  
Test Results ◽  
Cycle Fatigue

In February/March 2007, The NRC issued Regulatory Guide “RG1.207” and Argonne National Laboratory issued NUREG/CR-6909 that is now applicable in the US for evaluations of PWR environmental effects in fatigue analyses of new reactor components. In order to assess the conservativeness of the application of this NUREG report, Low Cycle Fatigue (LCF) tests were performed by AREVA NP on austenitic stainless steel specimens in a PWR environment. The selected material exhibits in air environment a fatigue behavior consistent with the ANL reference “air” mean curve, as published in NUREG/CR-6909. LCF tests in a PWR environment were performed at various strain amplitude levels (± 0.6% or ± 0.3%) for two loading conditions corresponding to a simple or to a complex strain rate history. The simple loading condition is a fully reverse triangle signal (for comparison purposes with tests performed by other laboratories with the same loading conditions) and the complex signal simulates the strain variation for an actual typical PWR thermal transient. In addition, two various surface finish conditions were tested: polished and ground. This paper presents the comparisons of penalty factors, as observed experimentally, with penalty factors evaluated using ANL formulations (considering the strain integral method for complex loading), and on the other, the comparison of the actual fatigue life of the specimen with the fatigue life predicted through the NUREG report application. For the two strain amplitudes of ± 0.6% and ± 0.3%, LCF tests results obtained on austenitic stainless steel specimens in PWR environment with triangle waveforms at constant low strain rates give “Fen” penalty factors close to those estimated using the ANL formulation (NUREG/6909). However, for the lower strain amplitude level and a triangle loading signal, the ANL formulation is pessimistic compared to the AREVA NP test results obtained for polished specimens. Finally, it was observed that constant amplitude LCF test results obtained on ground specimens under complex loading simulating an actual sequence of a cold and hot thermal shock exhibits lower combined environmental and surface finish effects when compared to the penalty factors estimated on the basis of the ANL formulations. It appears that the application of the NUREG/CR-6909 in conjunction with the Fen model proposed by ANL for austenitic stainless steel provides excessive margins, whereas the current ASME approach seems sufficient to cover significant environmental effects for representative loadings and surface finish conditions of reactor components.

The Effect of Muscle Loading on Internal Mechanical Parameters of the Lumbar Spine: A Finite Element Study

2011 ◽  
Author(s):  
Benjamin C. Gadomski ◽  
John Rasmussen ◽  
Christian M. Puttlitz
Keyword(s):  
Annulus Fibrosus ◽  
Critical Role ◽  
Complex Loading ◽  
Tissue Level ◽  
Mechanical Parameters ◽  
Loading Conditions ◽  
Additional Stability ◽  
Muscle Loading ◽  
Pure Moment

The human spine experiences complex loading in vivo; however, simplifications to these loading conditions are commonly made in computational and experimental protocols. Pure moments are often used in cadaveric preparations to replicate in vivo loading conditions, and previous studies have shown this method adequately predicts range of motion behavior (1, 2). It is unclear what effect pure moment loading has on the tissue-level internal mechanical parameters such as stresses in the annulus fibrosus and facet contact parameters. Recent advances in musculoskeletal modeling have elucidated previously unknown quantities of the musculature recruitment patterns such as times, forces, and directions. The advancements are especially relevant in cases of surgical intervention because the spinal musculature has been reported to play a critical role in providing additional stability to the spine when defects such as discectomy and nucleotomy are involved (2). Thus, the aim of the study was to determine the importance of computational loading conditions on the resultant global ranges of motion, as well as the tissue-level predictions of annulus fibrosus stresses, and facet contact pressures, forces, and areas.

Stress-Strain Relationship for Steel under Uniaxial Cyclic Loadings

2002 ◽  
Vol 5 (3) ◽  
pp. 143-151 ◽  
Author(s):  
Luís Calado ◽  
António Brito
Keyword(s):  
Complex Loading ◽  
Steel Structures ◽  
General Purpose ◽  
Loading Conditions ◽  
Stress Strain ◽  
Strain Relationship ◽  
Complete Failure ◽  
Loading Tests ◽  
Cyclic Loading Tests ◽  
Mathematical Relationships

The mechanical properties of steel in the inelastic range can generally be described by mathematical relationships. Many such constitutive relationships have been validated by static or uniaxial cyclic loading tests. Very few models have been substantiated by test results under complex loading conditions. For that reason, the implementation of such models in general purpose structural analysis programs for steel structures under seismic actions, is in some cases complex and in others impossible. This paper is concerned with a uniaxial non-linear model for structural steel under complex loading condition and with damage accumulation. The Giuffré, Menegoto and Pinto model was taken as a basis for the development of this model. The accuracy of the proposed numerical model was drawn with uniaxial cyclic experiments. Some numerical simulations are presented in order to illustrate the capabilities of the model for use as a stress-strain relationship for steel under uniaxial complex loading conditions up to the complete failure of the material.

Analysis of radial roller bearing rating life in complex loading conditions

2021 ◽  
pp. 1-27
Author(s):  
Vladimir Ivannikov ◽  
Mikhail Leontiev ◽  
Sergey Degtyarev ◽  
Valeriy Popov
Keyword(s):  
High Performance ◽  
Roller Bearing ◽  
Complex Loading ◽  
Contact Forces ◽  
Loading Conditions ◽  
Jet Engines ◽  
Inertia Effects ◽  
Internal Contact ◽  
Rolling Elements ◽  
Life Analysis

Abstract An approach for accurate life analysis of radial roller bearings in complex loading conditions is presented. It employs ISO~16281 and accounts not only for external radial loads applied to the inner ring, but also for (i) internal bearing clearance, (ii) flexibility of the bearing rings, (iii) rings out-of-roundness, (iv) inertia effects, (v) rolling elements profile and (vi) rings misalignment. In the last decades these factors have been becoming more and more important for modern high-performance jet engines, whose shafts are commonly hollow and the housing and the rings thicknesses may be of comparable magnitudes. To obtain the distribution of internal contact forces, an advanced static model of a bearing with deformable, potentially misaligned, rings is developed. The bending deformations of the rings are reproduced superimposing deformed shapes from each of the arising internal contact force applied individually. Bearing rollers are allowed to have non-cylindrical profile, its geometry is approximated by means of slices each having constant diameter. A robust numerical scheme for solving the resultant set of equations with the aid of the barrier functions method is constructed. To increase even further the accuracy of rating life analysis, distributions of the contact stresses between the roller and the ring surfaces, obtained by solving numerically the problem of non-Hertzian interaction, are added to computations. A numerical benchmark test is presented to demonstrate the applicability of the developed approach. It shows how the aforementioned factors influence the bearing contact forces and its rating life.

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