Fatigue Bending Strength of Jones Fracture Specific Screw Fixation

2017 ◽  
Vol 39 (4) ◽  
pp. 493-499 ◽  
Author(s):  
James Jastifer ◽  
Kirk A. McCullough
Keyword(s):  
Fatigue Strength ◽  
Bending Strength ◽  
Fatigue Testing ◽  
Screw Fixation ◽  
Optimal Choice ◽  
Fatigue Properties ◽  
Strength Data ◽  
Screw Design ◽  
Jones Fracture ◽  
Significant Difference

Background: Intramedullary screw fixation is a common method of treating proximal metadiaphyseal fifth metatarsal (ie, Jones) fractures. Fatigue failure is a complication of this fixation. There are many screw designs available, including Jones fracture specific fixation, but the optimal choice of screw design is unknown. The purpose of this study was to compare the fatigue strength of Jones fracture specific screw designs as well as other commonly used screw designs. Our hypothesis was that there would be no difference in fatigue strength for Jones fracture specific screw designs at similar screw diameters. Methods: A study was performed to determine the fatigue bending strength of 5 different screw designs including Jones fracture specific screw designs at 3 different screw diameters. Six screws of each size and design underwent cyclic fatigue testing, and a median fatigue limit (MFL) was determined for each screw design and size. Results: The Stryker Asnis JFX solid 4.0-mm, 5.0-mm, and 6.0-mm screws had a higher MFL than all other screws with similar diameter tested (all P < .0001). Both Jones fracture specific screw designs (Stryker Asnis JFX solid screws and Charlotte Carolina Jones screws) had higher MFLs than the other screw designs tested. Conclusion: This study provides comparative fatigue strength data on larger screw diameters, which have not been previously reported. There was a statistically significant difference in screw fatigue properties at the screw diameters tested. Clinical Relevance: The clinical significance of this study is that it provides surgeons with fatigue strength data to aid in screw selection for Jones fracture fixation.

An Experimental Method to Evaluate the Effect of Welding Residual Stress on Corrosion Fatigue Properties of Structural Steel in Synthetic Seawater

2018 ◽  
Vol 941 ◽  
pp. 1716-1721
Author(s):  
Yuko Ishibashi ◽  
Yoichi Kayamori
Keyword(s):  
Residual Stress ◽  
Fatigue Strength ◽  
Experimental Method ◽  
Corrosion Fatigue ◽  
Fatigue Testing ◽  
Diffraction Method ◽  
Welding Residual Stress ◽  
Tensile Residual Stress ◽  
Fatigue Properties ◽  
Synthetic Seawater

Tensile residual stress can cause a reduction in the fatigue strength of steel not only in air but also in corrosive environments. In air, for example, the effect of residual stress on fatigue strength can be estimated by using relations between fatigue strength and mean stress such as the modified Goodman diagram. However, it is not clear whether a sort of fatigue strength estimation can be applicable to corrosion fatigue properties. This paper presents an experimental method to evaluate the effect of welding residual stress on corrosion fatigue properties quantitatively, where corrosion fatigue tests were conducted in synthetic seawater by using characteristic fatigue specimens that have two parts, a tensile residual stress part and the other supporting part. Bead-on-plate welding was performed for applying welding residual stress in the tensile residual stress part. Residual stress relaxation was measured using the X-ray diffraction method in the midst of fatigue testing. Effects of tensile residual stress on corrosion pit growth and S-N curves were discussed.

The Relationship Between Tensile and Fatigue Strength of Friction Welded Steel Joints

2015 ◽  
Author(s):  
S. T. Selvamani ◽  
K. Palanikumar ◽  
K. Shanmugam ◽  
S. Divagar ◽  
M. Vigneshwar
Keyword(s):  
Fatigue Strength ◽  
Fatigue Testing ◽  
High Carbon Steel ◽  
Testing Machine ◽  
Fatigue Properties ◽  
Uniaxial Tensile ◽  
Sensitivity Factor ◽  
Welded Steel ◽  
Steel Joints ◽  
The Relationship

The friction welding of AISI 52100 grade low chromium and high carbon steel joints are investigated in this work to evaluate the fatigue life of the joints by conducting the experiments using servo hydraulic fatigue testing machine at different stress levels. All the experiments are conducted under uniaxial tensile loading condition (stress ratio=0). Fatigue strength, fatigue notch factor (Kf) and notch sensitivity factor (q) are evaluated for the optimized joints and the relationship between tensile and fatigue properties of Fully Deformed None (FDZ) is established. Finally, the Characteristics of friction welded joint is investigated with the help of Scanning Electron Microscope and Optical Microscopy under optimized condition.

scholarly journals The Role of Biomaterials in Upper Digestive Tract Transoral Reconstruction

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1436
Author(s):  
Raluca Grigore ◽  
Bogdan Popescu ◽  
Şerban Vifor Gabriel Berteşteanu ◽  
Cornelia Nichita ◽  
Irina Doinita Oașă ◽  
...  
Keyword(s):  
Shear Strength ◽  
Fatigue Strength ◽  
Ag Nanoparticles ◽  
Fatigue Testing ◽  
Biomechanical Properties ◽  
Optimal Choice ◽  
Implantable Devices ◽  
Surgical Reconstruction ◽  
Raman Spectrometry ◽  
Biomechanical Behavior

This study aims to establish whether the use of biomaterials, particularly polydimethylsiloxane (PDMS), for surgical reconstruction of the esophagus with templates, Montgomery salivary tube, after radical oncology surgery for malignant neoplasia is an optimal choice for patients’ safety and for optimal function preservation and organ rehabilitation. Structural analysis by Raman spectrometry and biomechanical properties with dynamic mechanical analysis are performed for fatigue strength and toughness, essential factors in durability of a prosthesis in the reconstruction practice of the esophagus. Nanocomposites with silicone elastomers and nanoparticles used in implantable devices and in reconstruction surgery present risks of infection and fatigue strength when required to perform a mechanical effort for long periods of time. This report takes into account the effect of silver (Ag) nanoparticles on the fatigue strength using polydimethylsiloxane (PDMS) matrix, representative for silicon elastomers used in implantable devices. PDMS with 5% (wt) Ag nanoparticles of 100–150 nm during mechanical fatigue testing at shear strength loses elasticity properties after 400 loading-unloading cycles and up to 15% shear strain. The fatigue strength, toughness, maximum shear strength, as well as clinical properties are key issues in designing Montgomery salivary tube and derivates with appropriate biomechanical behavior for each patient. Prosthesis design needs to indulge both clinical outcomes as well as design methods and research in the field of biomaterials.

Monotonic and Fatigue Testing of Polymer and Composite Materials Used in Heavy Duty Trucks

2019 ◽  
Author(s):  
Kevan W. F. Gahan ◽  
John P. Parmigiani
Keyword(s):  
Composite Materials ◽  
Fatigue Strength ◽  
Fatigue Testing ◽  
Flow Analysis ◽  
Testing Procedure ◽  
Standard Test ◽  
Fatigue Properties ◽  
Heavy Duty ◽  
Stress Strain ◽  
Mold Flow

Abstract Improved material models for engineered polymer and composite materials including both monotonic and fatigue characteristics are necessary for creating more accurate digital simulations for heavy duty trucks. Unlike steel and other alloys that are commonly included in truck designs, these advanced polymer materials do not have pre-existing fatigue characteristic data. Additionally, there are no individual standard test procedures that can be commonly cited and followed during a research program. These materials are found in hoods, dashboards, body panels and splash shields of trucks, and are subject to cyclic loading conditions at various amplitudes and durations throughout the entire use or “duty cycle” of the vehicle. The applied loads vary between truck models, as some trucks will be used for vocational purposes and others will remain on the highway. This paper describes the testing of isotropic non-reinforced, and anisotropic glass-fiber-reinforced polymers and the subsequent calculation of the monotonic and fatigue properties that are needed to describe their behavior under various loading conditions. Material characteristics are measured using a series of constant amplitude strain-controlled fatigue tests that follow standard practices from ASTM D638 (Standard Test Method for Tensile Properties of Plastics), ASTM E606 (Standard Practice for Strain-Controlled Fatigue Testing) methods, and SAE J1099 (Technical Report on Low Cycle Fatigue Properties of Ferrous and Non-Ferrous Materials). The ASTM D638 Type 1 coupon geometry is used for all materials, with a varied sample thickness and length. An axial extensometer is incorporated to measure strain data through the duration of all tests, and an anti-buckling fixture is installed during cyclic tests to eliminate any bending in the specimen during the compressive portion of the fully-reversed waveform. A transverse extensometer is also installed on the gauge length of the material coupons to measure instantaneous cross-sectional area as well as Poisson’s ratio during monotonic testing. The data collected through the monotonic testing procedure is used to calculate Young’s Modulus, Poisson’s ratio, ultimate tensile strength, elongation (% strain), yield strength and strain, and true fracture strength and strain. The fatigue testing procedure yields data that can be used to calculate the fatigue strength coefficient (σf′), fatigue strength exponent (b), fatigue ductility coefficient (εf′), and fatigue ductility exponent (c). These parameters provide accurate stress-strain, cyclic stress-strain, and strain-life curves for the materials in question. A method will also be suggested for calculating the stress-life fatigue parameters, stress range intercept and slope, from the strain-controlled data. Furthermore, mold-flow analysis is applied to predict general orientation of the reinforcement fibers induced by the direction of material flow as a part is injection-molded. The calculated monotonic and fatigue parameters in conjunction with mold-flow analysis can immediately be applied within digital s imulations, allowing improved accuracy in life-expectancy estimations for truck parts.

Fatigue Strength of Ion Nitrided Tool Steel

2006 ◽  
Vol 324-325 ◽  
pp. 475-478
Author(s):  
Mian Zhang ◽  
Shinichi Nishida ◽  
Nobusuke Hattori
Keyword(s):  
Fatigue Strength ◽  
Fatigue Test ◽  
Tool Steel ◽  
Surface Composition ◽  
Fatigue Testing ◽  
Testing Machine ◽  
Surface Hardness ◽  
Fatigue Properties ◽  
Ion Nitriding ◽  
Rotating Bending Fatigue

The authors have studied and clarified that ion nitriding was able to improve the fatigue properties of tool steel. Five kinds of ion nitriding methods (ion nitriding condition is different) were used in this study. The fatigue test had been performed using a rotating bending fatigue testing machine to investigate the effects of ion nitriding on fatigue properties of tool steel. The fractography was analyzed using a scanning electron microscope (SEM), and hardness distribution was also investigated using a microhardness tester. As a result, the fatigue strength and hardness of the ion nitrided specimen increased after ion nitriding processing. It is considered that the compressive residual stress which produced by ion nitriding processing in the layer reduced fatigue fracture, and the altered surface composition improved surface hardness. According to the results of the fatigue test, the optimal ion nitriding method on improving the fatigue limit of tool steel was determined. The hardness of the specimens remarkably increased after ion nitriding processing.

scholarly journals Statistical Modelling of the Fatigue Bending Strength of Norway Spruce Wood

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 536
Author(s):  
Jernej Klemenc ◽  
Gorazd Fajdiga
Keyword(s):  
Experimental Data ◽  
Fatigue Strength ◽  
Bending Strength ◽  
Mass Density ◽  
Statistical Modelling ◽  
Fatigue Properties ◽  
Novel Approach ◽  
Inverse Power Law ◽  
The Common ◽  
Constant Shape

When wood is used as a structural material, the fact that it is a highly inhomogeneous material, which significantly affects its static and fatigue properties, presents a major challenge to engineers. In this paper, a novel approach to modelling the fatigue-life properties of wood is presented. In the model, the common inverse-power-law relationship between the structural amplitude loads and the corresponding number of load cycles to failure is augmented with the influence of the wood’s mass density, the loading direction and the processing lot. The model is based on the two-parametric conditional Weibull’s probability density function with a constant shape parameter and a scale parameter that is a function of the previously mentioned parameters. The proposed approach was validated using the example of experimental static and fatigue-strength data from spruce beams. It turned out that the newly presented model is capable of adequately replicating the spruce’s S-N curves with a scatter, despite the relatively scarce amount of experimental data, which came from different production lots that were loaded in different directions and had a significant variation in density. Based on the experimental data, the statistical model predicts that the lower density wood has better fatigue strength.

Research on Properties of Coastal Natural Spherical Aggregate Concrete

2013 ◽  
Vol 838-841 ◽  
pp. 1810-1813
Author(s):  
Shuang Jian Jiao ◽  
Shuai Wang ◽  
Yong Guo
Keyword(s):  
Fatigue Strength ◽  
Bending Strength ◽  
Coastal Region ◽  
Fatigue Properties ◽  
Cement Concrete ◽  
Concrete Member ◽  
Spherical Aggregate ◽  
Cement Concrete Pavement ◽  
Engineering Significance ◽  
Stone Concrete

Our country has a long coastline and there are a lot of natural pebbles in coastal region. Applying natural pebbles in concrete is of great engineering significance and prospect. To measure the performance of coastal natural pebbles concrete and study the effect of aggregate on concrete properties, this article put forward a new comparison conditionthe same slump constant and cement dosage based on properties of coastal natural pebbles concrete and crushed stone concrete. Prepare different strength concrete under this condition. The compressive strength of pebble concrete is 100.5%110.7% times of stone concrete. The bending strength and fatigue strength are 97.8%108.1%, 135.8%176.6% respectively. This explains good static and fatigue properties of coastal natural pebbles. Pebble concrete has significant fatigue strength advantages in cement concrete pavement and concrete member under dynamic loading.

Study on the Bending Fatigue Properties of Nomex Fiber

2014 ◽  
Vol 1048 ◽  
pp. 62-65
Author(s):  
Guang Ming Cai ◽  
Xin Wang
Keyword(s):  
Fatigue Life ◽  
Fatigue Strength ◽  
Fatigue Testing ◽  
Ccd Camera ◽  
Fracture Morphology ◽  
Fatigue Properties ◽  
Bending Angle ◽  
Bending Fatigue ◽  
Different Temperatures ◽  
Bending Fatigue Strength

In this paper, we reported a bending fatigue testing apparatus which can test the bending fatigue properties of single Nomex fiber by setting the pretension, bending angle and temperature. The S-N and θ-N curves indicated that the pre-tension and bending angle had great influences on the bending fatigue life of Nomex fiber. A CCD camera was utilized to allow observation of the bending fatigue fracture morphology of fiber. It showed the fracture mechanism of Nomex fibers. The bending fatigue life of Nomex fiber was tested at different temperatures to show that its bending fatigue strength is strongly influenced by the temperature.

Effects of Roller Working and Ion Nitriding on Fatigue Properties of Eutectoid Steel

2007 ◽  
Vol 340-341 ◽  
pp. 519-524
Author(s):  
Mian Zhang ◽  
Shinichi Nishida ◽  
Nobusuke Hattori ◽  
Wen Xian Sun
Keyword(s):  
Fatigue Strength ◽  
Fatigue Test ◽  
Fatigue Testing ◽  
Testing Machine ◽  
Surface Hardness ◽  
Fatigue Properties ◽  
Eutectoid Steel ◽  
Ion Nitriding ◽  
Rotating Bending Fatigue ◽  
Rotating Bending

In this study, the authors have investigated and compared the effects of roller working and ion nitriding on fatigue properties of eutectoid steel. Five kinds of roller worked and two kinds of ion nitrided specimens were used in this test. The fatigue test was performed using a rotating bending fatigue testing machine to evaluate the fatigue strength of roller worked and ion nitrided eutectoid steel. The fatigue test result shows that roller working is more effective on improving the fatigue strength of the material than ion nitriding. On the other hand, the ion nitriding can much greatly increase the surface hardness than the roller working. In the case of roller working, the fatigue properties are improved by the three main factors which are compressive residual stress, work hardening and fiberized micro-structure.

Influence of Plasma Radical Nitriding on Fatigue Properties of SCM435 Steel

2007 ◽  
Vol 353-358 ◽  
pp. 266-269
Author(s):  
Nu Yan ◽  
I. Lee ◽  
Riichi Murakami ◽  
Daisuke Yonekura ◽  
J. Sun ◽  
...  
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Fatigue Strength ◽  
Intensity Factor ◽  
Fatigue Testing ◽  
Testing Machine ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Scm435 Steel ◽  
Nitrided Specimen

The effect of plasma radical nitriding treatment on fatigue properties of SCM435 steel in super long life region was investigated. Fatigue tests were carried out using a dual-spindle rotating bending fatigue-testing machine at room temperature in air for the specimens nitrided at 773 K and 823 K for 3 hrs. The fatigue strength of nitrided specimen was greater than that of un-nitrided specimen and the crack initiation mode changed from the surface cracking of un-nitrided specimen to the subsurface cracking of nitrided specimen. Hardening layer and compressive residual stress were formed by nitriding, which resulted in the improvement of the fatigue strength. The stress intensity factor was calculated using facet area in Fish-eye fracture mode. As a result, the stress intensity factor indicated almost constant value, ~ 3-4 MPa·m1/2, regardless of the number of cycles to failure.

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