scholarly journals A Novel Screw Drive for Allogenic Headless Position Screws for Use in Osteosynthesis—A Finite-Element Analysis

2021 ◽  
Vol 8 (10) ◽  
pp. 136
Author(s):  
Sebastian Lifka ◽  
Werner Baumgartner

Due to their osteoconductive properties, allogenic bone screws made of human cortical bone have advantages regarding rehabilitation compared to other materials such as stainless steel or titanium. Since conventional screw drives like hexagonal or hexalobular drives are difficult to manufacture in headless allogenic screws, an easy-to-manufacture screw drive is needed. In this paper, we present a simple drive for headless allogenic bone screws that allows the screw to be fully inserted. Since the screw drive is completely internal, no threads are removed. In order to prove the mechanical strength, we performed simulations of the new drive using the Finite-Element method (FEM), validated the simulations with a prototype screw, tested the novel screw drive experimentally and compared the simulations with conventional drives. The validation with the prototype showed that our simulations provided valid results. Furthermore, the simulations of the new screw drive showed good performance in terms of mechanical strength in allogenic screws compared to conventional screw drives. The presented screw drive is simple and easy to manufacture and is therefore suitable for headless allogenic bone screws where conventional drives are difficult to manufacture.

1998 ◽  
Vol 26 (2) ◽  
pp. 109-119 ◽  
Author(s):  
M. Koishi ◽  
K. Kabe ◽  
M. Shiratori

Abstract The finite element method has been used widely in tire engineering. Most tire simulations using the finite element method are static analyses, because tires are very complex nonlinear structures. Recently, transient phenomena have been studied with explicit finite element analysis codes. In this paper, the authors demonstrate the feasibility of tire cornering simulation using an explicit finite element code, PAM-SHOCK. First, we propose the cornering simulation using the explicit finite element analysis code. To demonstrate the efficiency of the proposed simulation, computed cornering forces for a 175SR14 tire are compared with experimental results from an MTS Flat-Trac Tire Test System. The computed cornering forces agree well with experimental results. After that, parametric studies are conducted by using the proposed simulation.


1980 ◽  
Vol 47 (2) ◽  
pp. 377-382 ◽  
Author(s):  
K. Miya ◽  
T. Takagi ◽  
Y. Ando

Some corrections have been made hitherto to explain the great discrepancy between experimental and theoretical values of the magnetoelastic buckling field of a ferromagnetic beam plate. To solve this problem, the finite-element method was applied. A magnetic field and buckling equations of the ferromagnetic beam plate finite in size were solved numerically assuming that the magnetic torque is proportional to the rotation of the plate and by using a disturbed magnetic torque deduced by Moon. Numerical and experimental results agree well with each other within 25 percent.


2014 ◽  
Vol 852 ◽  
pp. 447-451
Author(s):  
Yan Fang Yue ◽  
Zhi Bo Xin ◽  
Jin Ye Wang

The finite element method was applied in the construction design of the welding column of CNC boring machine for dynamic analysis and modal analysis. The laws of deformation and stress of a loaded column were obtained, and the natural frequency of each step and modes of column were also given according to this method. The results implied that the strength and the stiffness of welding column were met the machining requirements. Machine working frequency far less than inherent frequency, thus resonance is not easy to occur. Through the way, the optimization proposals of structure were given.


1988 ◽  
Vol 16 (3) ◽  
pp. 128-145 ◽  
Author(s):  
T. C. Warholic ◽  
R. G. Pelle

Abstract The molding process is a critical step in the manufacture of pneumatic tires. It affects the design and consequently the performance of the tire. The present paper covers work aimed at analyzing the molding process using the finite element method. Specifically, the finite element code MARC is used to analyze the inflation of a curing bladder inside a rigid tire profile. Incompressible elements are used to model the bladder and GAP elements are used to simulate the contact between the two surfaces. Of primary interest is the bladder-profile interface, namely how contact occurs at the interface and the magnitude and uniformity of the interfacial pressures. Two different bladder shapes and two different inside tire profiles are studied. Of equal importance is the ability to model this type of contact problem as it is a significant step toward analyzing the tire molding process.


2012 ◽  
Vol 557-559 ◽  
pp. 2126-2129
Author(s):  
Jun Hui Zhu ◽  
Chun Rui Cheng ◽  
Guang Pu Lou

Finite element methods for the elliptic variational inequality of the second kind deduced from friction problems or nonlinear materials in elasticity have been discussed. In this paper, the finite element method with numerical integration for the second type elliptic variational inequality is considered and an error estimate is proved.


1998 ◽  
Vol 120 (2) ◽  
pp. 143-148 ◽  
Author(s):  
N. Huber ◽  
Ch. Tsakmakis

Using the Finite Element Method, an analysis is given of the indentation of an elasticplastic half-space by a rigid sphere. In particular, attention is focused on the effect of hardening rules on the material response. The materials considered are supposed to exhibit isotropic and kinematic hardening. Moreover, it is shown that the possibility of similar behavior due to effects of friction can be ruled out.


2021 ◽  
Author(s):  
Muhammad Ardalani-Farsa

The finite element method has been applied in the area of the cervical spine since the 1970's. In the present research work, the finite element method was employed to model, validate and analyze a complete model of the human cervical spine from C1 to T1, including interconnecting intervertebral discs, ligaments and joints. The developed model of the cervical spine was validated by the experimental results presented in the literature. As the values obtained from the finite element analysis were mainly in the range of motion observed in the experiment; it was concluded that the finite element results were consistent with the reported data in the literature. Next, the validated model of the cervical spine was examined under physiological loading modes to locate the areas bearing maximum stress in the cervical spine. Finally, to study the effect of variations in the material properties on the output of the finite element analysis, a material property sensitivity study was conducted to the C3-T1 model of cervical spine. Changes in the material properties of the soft tissues affected the external and internal responses of both the hard and soft tissue components, while changes in those of the hard tissues only affected the internal response of hard tissues.


Author(s):  
A. Carnero ◽  
J. Kubiak ◽  
A. López

Abstract Frequent failures of long turbine blades forced an electrical utility to sponsor research work to find out the causes of the failures. One of the techniques applied in this work was finite element analysis. The paper presents an application of the finite element method for computation of the natural frequencies, steady-state and alternating stresses, deformations due to forces acting on the blades and modal shapes of the turbine long blade groups. Two stages, L-1 and L-0 of the low pressure part of a steam turbine, were analyzed. It has been postulated that the results of the FEM analysis of the blades groups would be complementary to those obtained from the radio telemetry test (which was carried out during operation of the turbine) for the purpose of blade group failure diagnosis. However, the results of the analysis show that the FEM results were decisive in blade failure identification (L-1 stage moving blades). The graphical post processor of the FEM code revealed that the first blade in the group was the one most protruding from the stage rotating plane, thus indicating that this blade was the most prone to erosion. This was confirmed in the inspection of the turbine. This finding showed why only the first blade in the group was cracked (erosion induced cracks). The mode shapes were also very helpful in identifying other types of cracks which affected other parts of the blades. It can be concluded that the finite element method is very useful for identification of very difficult cases of blade faults and indispensable for carrying out modifications to prevent future failures.


Sign in / Sign up

Export Citation Format

Share Document