Effect of Interface Damage on Loosening Behavior of Acetabular Cup Subjected to Cyclic Loading

2018 ◽  
Vol 941 ◽  
pp. 1841-1845 ◽  
Author(s):  
Yuichi Otsuka ◽  
Kengo Kagaya ◽  
Yuki Hakozaki ◽  
Yukio Miyashita ◽  
Yoshiharu Mutoh
Keyword(s):  
Cyclic Loading ◽  
Mechanical Loading ◽  
Failure Modes ◽  
Fatigue Testing ◽  
Biological Effects ◽  
Stress Singularity ◽  
Testing System ◽  
Acetabular Cup ◽  
Edge Part ◽  
The One

This study aims at experimentally revealing the effects of damages/fractures in HAp coating layer of acetabular cups on loosening behavior of the acetabular cups. Aseptic loosening is occurred due to degradation of fixing force of acetabular cups by biological effects or mechanical loading. However, effects of mechanical loading on loosening behaviour have not been observed yet. In order to simulate cyclic loading conditions of gaits, a testing system which can load entire components of joint including acetabular cups and stem parts was designed. Moreover, by applying two positions of AE sensors during fatigue testing, it was possible to observe the damage behavior of HAp coating. AE measurement detected different failure modes of HAp coating, which were locally occurred at an edge part of the acetabular cup due to stress singularity at that region. In the cases of changing fixation angles, even though damages in simulated cancellous bone surrounding acetabular cups were less occurred, extents of rotational displacements were compatible with the one in an original fixation angle.

Fatigue of Unidirectional Cord-Rubber Composites

1999 ◽  
Vol 27 (1) ◽  
pp. 48-57 ◽  
Author(s):  
Y. Liu ◽  
Z. Wan ◽  
Z. Tian ◽  
X. Du ◽  
J. Jiang ◽  
...  
Keyword(s):  
Damage Accumulation ◽  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Constant Load ◽  
Testing System ◽  
Rubber Composites ◽  
Cycle Frequency ◽  
Periodic Loading ◽  
Fatigue Damage Accumulation ◽  
Rubber Composite

Abstract A fatigue testing system is established with which the real-time recording of stress, strain, temperature, and hysteresis loss of rubbers or cord-rubber composite specimens subjected to periodic loading or extension can be successfully carried out. Several problems are connected with the experimental study of the fatigue of rubber composites. In constant extension cycling, the specimen becomes relaxed because of the viscoelasticity of rubber composites, and the imposed tension-tension deformation becomes complex. In this method, the specimen is unlikely to fail unless the imposed extensions are very large. Constant load cycling can avoid the shortcomings of constant extension cycling. The specially designed clamps ensure that the specimen does not slip when the load retains a constant value. The Deformation and fatigue damage accumulation processes of rubber composites under periodic loading are also examined. Obviously, the effect of cycle frequency on the fatigue life of rubber composites can not be ignored because of the viscoelasticity of constituent materials. The increase of specimen surface temperature is relatively small in the case of 1 Hz, but the temperature can easily reach 100°C at the 8 Hz frequency. A method for evaluating the fatigue behavior of tires is proposed.

scholarly journals Fatigue Stress-Life Model of RC Beams Based on an Accelerated Fatigue Method

2019 ◽  
Vol 4 (2) ◽  
pp. 16
Author(s):  
Eljufout ◽  
Toutanji ◽  
Al-Qaralleh
Keyword(s):  
Cyclic Loading ◽  
Fatigue Testing ◽  
Three Dimensional ◽  
Rc Beam ◽  
Rc Beams ◽  
Testing Methods ◽  
Load Range ◽  
Fatigue Stress ◽  
Life Model ◽  
Prediction Band

Several standard fatigue testing methods are used to determine the fatigue stress-life prediction model (S-N curve) and the endurance limit of Reinforced Concrete (RC) beams, including the application of constant cyclic tension-tension loads at different stress or strain ranges. The standard fatigue testing methods are time-consuming and expensive to perform, as a large number of specimens is needed to obtain valid results. The purpose of this paper is to examine a fatigue stress-life predication model of RC beams that are developed with an accelerated fatigue approach. This approach is based on the hypothesis of linear accumulative damage of the Palmgren–Miner rule, whereby the applied cyclic load range is linearly increased with respect to the number of cycles until the specimen fails. A three-dimensional RC beam was modeled and validated using ANSYS software. Numerical simulations were performed for the RC beam under linearly increased cyclic loading with different initial loading conditions. A fatigue stress-life model was developed that was based on the analyzed data of three specimens. The accelerated fatigue approach has a higher rate of damage accumulations than the standard testing approach. All of the analyzed specimens failed due to an unstable cracking of concrete. The developed fatigue stress-life model fits the upper 95% prediction band of RC beams that were tested under constant amplitude cyclic loading.

Electrical Resistance and Acoustic Emission During Fatigue Testing of Pristine and High Velocity Impact SiC/SiC Composites at Room and Elevated Temperature

2016 ◽  
Author(s):  
Zipeng Han ◽  
Gregory N. Morscher ◽  
Emmanuel Maillet ◽  
Manigandan Kannan ◽  
Sung R. Choi ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Acoustic Emission ◽  
Cyclic Loading ◽  
Electrical Resistance ◽  
Fatigue Testing ◽  
Early Stage ◽  
Loading Conditions ◽  
Initial Attempt ◽  
Matrix Cracks ◽  
Sic Composites

Electrical resistance (ER) is a relatively new approach for real-time monitoring and evaluating damage in SiC/SiC composites for a variety of loading conditions. In this study, ER of woven silicon carbide fiber-reinforced silicon carbide composite systems in their pristine and impacted state were measured under cyclic loading conditions at room and high temperature (1200C). In addition, modal acoustic emission (AE) was also monitored, which can reveal the occasion of matrix cracks and fiber. ER measurement and AE technique are shown in this study to be useful methods to monitor damage and indicate the failure under cyclic loading. Based on the slope of the ER evolution, an initial attempt has been made to develop a method allowing a critical damage phase to be identified. While the physical meaning of the critical point is not yet clear, it has the potential to allow the failure to be indicated at its early stage.

scholarly journals Rolling Wear of Silicon Nitride Bearing Materials

1990 ◽  
Author(s):  
John W. Lucek
Keyword(s):  
Fatigue Life ◽  
Silicon Nitride ◽  
Failure Modes ◽  
Fatigue Testing ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Wear Performance ◽  
Wear Rates ◽  
Bearing Materials

Rolling-contact fatigue test methods were used to measure the wear performance of several silicon nitride materials. Sintered, hot pressed and hot isostatically pressed materials exhibited wear rates ranging over three orders of magnitude. Hot isostatically pressed materials had the lowest wear rates. Despite the disparity in wear performance, all materials tested had useful rolling-contact fatigue lives compared to steel. Fatigue life estimates, failure modes, and rolling wear performance for theses ceramics are compared to M-50 steel. This work highlights the rapid contact stress reductions that occur due to conformal wear in rolling-contact fatigue testing. Candidate bearing materials with unacceptably high wear rates may exhibit useful fatigue lives. Rolling contact bearing materials must possess useful wear and fatigue resistance. Proper performance screening of candidate bearing materials must describe the failure mode, wear rate, and the fatigue life. Guidelines for fatigue testing methods are proposed.

In Vitro Stain Transport in Canaliculi of Rat Femora Under Cyclic Loading

2000 ◽  
Author(s):  
Bixia Li ◽  
Timothy L. Norman
Keyword(s):  
Fluid Flow ◽  
Cyclic Loading ◽  
Confocal Microscopy ◽  
Mechanical Loading ◽  
Cyclic Load ◽  
Flow Behavior ◽  
Load Level ◽  
Static Conditions ◽  
Rat Bone

Abstract In this study, rat femurs were used to test the diffusion and mechanical transport properties of a fluroscein stain tracer in microvessels of bone. Fluroscein was used as a tracer to visualize the fluid flow behavior using confocal microscopy. It was found that stain transport occurs due to diffusion under static conditions and due to mechanical loading. The transport increased with cyclic load level and frequency. Our results also show that stain transport at the canaliculi level occurs rapidly in rat bone.

Influence of Cyclic Loading on Mechanical Loosening of Hinged Knee Prostheses

1978 ◽  
Vol 7 (4) ◽  
pp. 235-239 ◽  
Author(s):  
D. H. van Campen ◽  
H. W. Croon ◽  
J. Lindwer
Keyword(s):  
Experimental Investigation ◽  
Cyclic Loading ◽  
Mechanical Loading ◽  
Knee Prosthesis ◽  
In Vitro Experiments ◽  
Knee Prostheses ◽  
Normal Walking ◽  
Fresh Cadaver ◽  
Unfavourable Effect

A combined theoretical and experimental investigation is reported with respect to the influence of mechanical loading on loosening at the cement bone interface of knee prostheses with intermedullary stems. The in vitro experiments have been performed under cyclic loading conditions with the tibial part of a Shiers knee prosthesis implanted in fresh cadaver tibiae. The experimental results indicate an unfavourable effect of peak loading (as occurring in walking up stairs) on loosening as compared with loading due to normal walking conditions.

scholarly journals Analisa uji ketahanan fatigue Aluminium scrap hasil remelting sepatu rem (brake shoe) terhadap variasi beban menggunakan tipe rotary bending

2020 ◽  
Vol 1 (2) ◽  
pp. 96-107
Author(s):  
Wahyono Wahyono ◽  
Eko Nugroho ◽  
Sulis Dri Handono ◽  
Eko Budiyanto
Keyword(s):  
Yield Strength ◽  
Fatigue Test ◽  
Fatigue Testing ◽  
Literature Study ◽  
Brake Shoe ◽  
Wheeled Vehicle ◽  
Best Value ◽  
Material Fracture ◽  
The One ◽  
Aluminum Material

Used brake shoes are a component of a two-wheeled vehicle that has a type of aluminum material. Therefore, we can do remelting aluminum from brake shoes that can no longer be used for advanced application use and utilization of brake shoe waste which still has a sale value. This study aims to determine the best value or the one that approximates the fatigue limit endurance value of each loading variation given to the specimen and to determine the characteristics of the fracture surface from the differences in given loading. The research method used for fatigue testing is by using a literature study and direct observation or observation. Before doing the fatigue testing, first, do the tensile test to get the yield strength value where this value is used for the loading that will be given to the fatigue test, the loading variations are given for the fatigue test are 40%, 50%, and 60 % of the yield strength value. From the results of fatigue testing at a load of 60% with the stress of 100.2 MPa and a given load of 3.81 kg, it can be seen that the value of material fracture at 27,421 cycles and in the timeframe 00:18:16. Then at 50% loading with the stress of 83.5 MPa and a given load of 3.18 g, it can be seen that the fracture value of the material in the 51,659 cycles in the fracture period is 00:34:35. Then in the next test with a load of 40% and given the stress of 66.8 MPa and a load of 2.5 kg, it is known that the fracture value of the material in the 106,930 cycles in the fracture period reaches 01:11:17. From the test data, it can be concluded that the ratio between cycle and time with voltage is inversely proportional, that is, the smaller the voltage the greater the cycle and time obtained, and vice versa, the greater the voltage, the smaller the cycle and time will be obtained. Keywords: Used brake shoes, Aluminum, Remelting, load variation, fatigue test.

scholarly journals Plasticity based interface model for failure modelling of unreinforced masonry under cyclic loading

2020 ◽  
Vol 42 (3) ◽  
pp. 321-338
Author(s):  
P. V. S. K. Kumar ◽  
Amirtham Rajagopal ◽  
Manoj Pandey
Keyword(s):  
Cyclic Loading ◽  
Yield Surface ◽  
Failure Modes ◽  
Back Stress ◽  
Unreinforced Masonry ◽  
Interface Model ◽  
Linear Set ◽  
Mixed Hardening ◽  
Hardening Law ◽  
Backward Integration

In this work our objective is to understand the failure behaviour of unreinforced masonry under in-plane cyclic loading. For this purpose we proposed a plasticity based interface model consists of a single yield surface criteria which is a direct extension of Mohr-Coulomb criteria with a tension cut and compression cap and a back stress vector is introduced as a mixed hardening law variable  in the adopted yield surface to capture the unloading/reloading behaviour of masonry under cyclic loading. A simplified micromechanical interface modelling approach is adopted to capture all the failure modes of masonry. The integration of the differential constitutive equation is  done by using implicit Euler backward integration approach and the obtained non-linear set of equations are solved by a combined local/global Newton solver. The proposed constitutive model  is implemented in ABAQUS by writing  UMAT (user-defined subroutine) and the obtained numerical results are compared with  experimental results available in the literature.

Constitutive Modeling of Force-Controlled Fatigue Testing in Human Meniscus Tissue

2020 ◽  
Author(s):  
Bradley Scott Henderson
Keyword(s):  
Damage Mechanics ◽  
Failure Modes ◽  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Damage Model ◽  
Viscoelastic Model ◽  
Knee Injuries ◽  
Fatigue Loading ◽  
The United States ◽  
Meniscus Tissue

The meniscus is a wedge-shaped fibrocartilaginous tissue located between the femur and tibia that helps stabilize the knee and protect the underlying cartilage. There are 2.5 million reported knee injuries each year, making it the most injured joint in the human body. Nearly twenty percent of these injuries are due to a torn meniscus, leading to over half a million meniscus surgeries performed in the United States annually. Therefore, it is critical to understand the failure modes of meniscus tissue to prevent these debilitating injuries. A failure mode that accounts for one-third of all meniscus injuries is repeated exposure to low-magnitude tensile loads, known as fatigue. One approach to gain physical insight into fatigue mechanisms is through cyclic tensile experiments performed in laboratories. An alternative approach is to use constitutive mathematical models that predict and describe the material's behavior. These models can avoid the expense and time required for experimental fatigue studies, but they also must be calibrated and validated using experimental data. The aim of this study is to validate a constitutive model to predict human meniscus' observed fatigue behavior in force-controlled loading. Three variations of constitutive models were applied to test each model's ability to model fatigue induced creep. These models included a viscoelastic damage model, a continuum damage mechanics model, and a viscoelastic model. Using a custom program, each models' parameters were fit to stretch-time plots from previously performed fatigue experiments of cadaveric human meniscus. The quality of fit for each model was then measured. The results of this study show that a viscoelastic damage formulation can effectively fit force-controlled fatigue behavior and, on average, performed the best of the three models presented. On average, the resulting NRMSE values for stretch at all creep stages were 0.22%, 2.03%, and 0.45% for the visco-damage, damage-only, and visco-only models, respectively. The requirement of including both viscoelasticity and damage to model all three creep stages indicates that viscoelasticity may be the driving factor for damage accumulation in fatigue loading. Further, the relatively low damage values, ranging from 0.05 to 0.2, right before exponential increases in stretch, indicate that failure may occur from fatigue loading without a considerable accumulation of damage. The validation results showed that the model could not completely represent pull to failure experiments when using material parameters that curve fit fatigue experiments. Still, they indicated that the combination of discontinuous CDM and viscoelasticity shows potential to model both fatigue and static loadings using a single formulation. To our knowledge, this is the first study to model force-controlled fatigue induced creep in the meniscus or any other soft tissue. This study's results can be utilized to further model force-controlled fatigue to predict and prevent meniscus tissue injuries.

Sign in / Sign up

Export Citation Format

Share Document