Finite Element Analysis of Laser Fabricated Microjoint Performance in Cerebrospinal Fluid

2007 ◽  
Author(s):  
Ahsan Mian ◽  
Jesse Law
Keyword(s):  
Finite Element ◽  
Cerebrospinal Fluid ◽  
Mechanical Performance ◽  
Degradation Mechanism ◽  
Polyimide Film ◽  
Element Analysis ◽  
Critical Feature ◽  
Artificial Cerebrospinal Fluid ◽  
Bond Degradation ◽  
Before And After

Assessment of neural biocompatibility requires that materials be tested with exposure in neural fluids. Laser bonded microjoint samples made from titanium foil and polyimide film (TiPI) were evaluated for mechanical performance before and after exposure in artificial cerebrospinal fluid (CSF) for two, four and twelve weeks at 37°C. These samples represent a critical feature i.e., the microjoint — a major weakness in the bioencapsulation system. The laser microbonds showed initial degradation up to four weeks which then stabilized afterwards and retained similar strength until twelve weeks. To understand this bond degradation mechanism better, a finite element modeling approach was adopted. From the finite element results, it was revealed that the bond degradation was not owing to the hygroscopic expansion of polyimide. Rather, relaxation of the process induced residual stresses may have resulted in weakening of the bond strength as observed from experimental measurements.

Weight-Reduction Optimization Design for Milling Planer Bed Based on Finite Element Analysis

2012 ◽  
Vol 490-495 ◽  
pp. 2785-2789
Author(s):  
Dong Sun ◽  
Xu Dong Yang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Weight Reduction ◽  
Optimization Design ◽  
Weak Link ◽  
Three Dimensional ◽  
Production Costs ◽  
Element Analysis ◽  
Before And After ◽  
Improvement Scheme

The milling planer bed is one of the most important foundational parts for the entire machine, sufficient stiffness is required. The posterior segment of a certain milling planer bed is regarded as the optimization object in this paper. Three-dimensional modeling method is used to calculate the exact weight of the bed and then finite element analysis is used to research the static and dynamic characteristics before and after weight-reduction. The weak link of the bed is found out and a improvement scheme is put forward ensuring lower production costs under the premise of sufficient rigidity.

scholarly journals Finite Element Analysis on Behavior of Reinforced Hollow High Strength Concrete Filled Square Steel Tube Short Columns under Axial Compression

2021 ◽  
Vol 2101 (1) ◽  
pp. 012059
Author(s):  
Z J Yang ◽  
X Li ◽  
G C Li ◽  
S C Peng
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Strength Concrete ◽  
Mechanical Performance ◽  
Concrete Strength ◽  
High Strength ◽  
Steel Tube ◽  
Element Analysis ◽  
Steel Strength ◽  
Square Steel Tube

Abstract Hollow concrete-filled steel tubular (CFST) member is mainly adopted in power transmission and transformation structures, but when it is used in the superstructure with complex stress, the hollow CFST member has a low bearing capacity and is prone to brittle failure. To improve the mechanical performance of hollow CFST members, a new type of reinforced hollow high strength concrete-filled square steel tube (RHCFSST) was proposed, and its axial compression performance was researched. 18 finite element analysis (FEA) models of axially loaded RHCFSST stub columns were established through FEA software ABAQUS. The whole stress process of composite columns was studied, and parametric studies were carried out to analyze the mechanical performance of the member. Parameters of the steel strength, steel ratio, deformed bar and sandwich concrete strength were varied. Based on the simulation results, the stress process of members can be divided into four stages: elastic stage, elastoplastic stage, descending stage and gentle stage. With the increase of steel strength, steel ratio, the strength of sandwich concrete and the addition of deformed bars, the ultimate bearing capacity of members also increases. Additionally, the increment of those parameters will improve the ductility of the member, except for the sandwich concrete strength.

Calculation methods of bridge deck for prestressed short rib T-beam bridges

2020 ◽  
pp. 1-13
Author(s):  
Sijia Wang ◽  
Tianlai Yu
Keyword(s):  
Finite Element ◽  
Bridge Deck ◽  
Mechanical Performance ◽  
Test Results ◽  
Analysis Method ◽  
Slab Method ◽  
Element Analysis ◽  
Calculation Results ◽  
Beam Bridge ◽  
T Beam

Because of the low height of the prestressed short rib T-beam bridge and the poor torsion resistance of the main beam, the positive moment in the middle span of the bridge deck will increase correspondingly compared with the normal rib beam bridge. At present, there is little research on the calculation method of the bridge deck of the prestressed short rib T-beam bridge. In this paper, the space finite element method and the continuous one-way slab method are used to calculate the forces on the bridge deck, based on the space finite element method, a finite element elastic supported continuous beam method is proposed to calculate the forces on the bridge deck. By comparing the calculation results of the three methods with the test results, the reasonable calculation method of the bridge deck is studied. The results show that the spatial finite element analysis method can simulate the mechanical performance of the deck of the bridge of the prestressed short rib T-beam bridge well, the stress calculation results are consistent with the test results, and the calculation accuracy is high, which can be used in the actual engineering design; The finite element analysis method of elastic support continuous beam can also simulate the mechanical performance of the deck of the bridge of the prestressed short rib T-beam bridge. The concept of the method is clear, the calculation is convenient, and it is more suitable for the application of engineering design; The calculation results of the continuous one-way slab method are too large to be safe for design.

scholarly journals New Dental Implant with 3D Shock Absorbers and Tooth-Like Mobility—Prototype Development, Finite Element Analysis (FEA), and Mechanical Testing

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3444
Author(s):  
Avram Manea ◽  
Grigore Baciut ◽  
Mihaela Baciut ◽  
Dumitru Pop ◽  
Dan Sorin Comsa ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Mechanical Testing ◽  
Alveolar Bone ◽  
Mechanical Performance ◽  
Implant Design ◽  
Element Analysis ◽  
Prototype Development ◽  
Second Stage ◽  
Testing Protocol

Background: Once inserted and osseointegrated, dental implants become ankylosed, which makes them immobile with respect to the alveolar bone. The present paper describes the development of a new and original implant design which replicates the 3D physiological mobility of natural teeth. The first phase of the test followed the resistance of the implant to mechanical stress as well as the behavior of the surrounding bone. Modifications to the design were made after the first set of results. In the second stage, mechanical tests in conjunction with finite element analysis were performed to test the improved implant design. Methods: In order to test the new concept, 6 titanium alloy (Ti6Al4V) implants were produced (milling). The implants were fitted into the dynamic testing device. The initial mobility was measured for each implant as well as their mobility after several test cycles. In the second stage, 10 implants with the modified design were produced. The testing protocol included mechanical testing and finite element analysis. Results: The initial testing protocol was applied almost entirely successfully. Premature fracturing of some implants and fitting blocks occurred and the testing protocol was readjusted. The issues in the initial test helped design the final testing protocol and the new implants with improved mechanical performance. Conclusion: The new prototype proved the efficiency of the concept. The initial tests pointed out the need for design improvement and the following tests validated the concept.

scholarly journals Finite element analysis of T-joint of mechanical connecting channels

2020 ◽  
Vol 12 (12) ◽  
pp. 168781402097774
Author(s):  
Jiawei Wang ◽  
Fachao Li ◽  
Zibo Chen ◽  
Baishu Li ◽  
Jue Zhu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Rail Transit ◽  
Force Analysis ◽  
Analysis Model ◽  
Element Analysis ◽  
Finite Element Analysis Model ◽  
Before And After ◽  
Design Software

This paper studies the force and deformation of the connecting channel in Ningbo rail transit construction, which firstly used the mechanical shield method. Steel-concrete composite structural segments are used in the T-joint of connecting channel. The cutting part of the segments are replaced by the concrete and fiberglass instead of reinforced concrete. Basing on a variety of three-dimensional design software and ABAQUS finite element analysis software, a refined finite element analysis model of the special segments is established. By considering the influence of curved joint bolts, the force analysis of the special segments under the structural state before and after construction is performed. According to the analysis and comparison of the deformation of the segments with and without the bolts, it is concluded that the steel-concrete segments can withstand the pressure of the soil before and after the construction. Suggestions for the safety of the design and construction of the segments are put forward.

Central role for angiotensin in control of adrenal catecholamine secretion

1985 ◽  
Vol 248 (3) ◽  
pp. R363-R370 ◽  
Author(s):  
E. J. Corwin ◽  
J. F. Seaton ◽  
M. Hamaji ◽  
T. S. Harrison
Keyword(s):  
Cerebrospinal Fluid ◽  
Catecholamine Secretion ◽  
Ang Ii ◽  
Artificial Cerebrospinal Fluid ◽  
Ventriculocisternal Perfusion ◽  
Before And After ◽  
Adrenal Response ◽  
Adrenal Secretion ◽  
Lateral Cerebral Ventricle

Angiotensin II (ANG II) is required for unimpaired adrenal reflex secretion of catecholamines after hemorrhage in the dog. To test if ANG II acts centrally, experiments were performed under general anesthesia on bilaterally or sham-nephrectomized dogs hemorrhaged at 25 ml/kg. Ventriculocisternal perfusion of ANG II or its antagonist saralasin was accomplished via needles inserted in the left lateral cerebral ventricle and cisterna magna. Mean arterial pressure and adrenal secretion of catecholamines were measured before and after hemorrhage. Nephrectomized dogs receiving only artificial cerebrospinal fluid (CSF) by ventriculocisternal perfusion had a very small adrenal response to hemorrhage compared with animals receiving ANG II intraventricularly (IVT) (at 10 and 100 pg . kg-1 . min-1). This effect of ANG II IVT also depended on the rate of IVT infusion. Peripheral infusion of ANG II (10 pg . kg-1 . min-1) had no effect on adrenal catecholamine secretion. Animals with intact kidneys given saralasin IVT (0.06 ng/min) responded similarly to nephrectomized dogs receiving only CSF IVT. Intravenous saralasin did not blunt the response to hemorrhage. Thus ANG II appears to support catecholamine secretion via a central mechanism. This mechanism is physiologically significant because either nephrectomy or functional elimination of ANG II by saralasin greatly attenuates the adrenal medullary response to hemorrhage in vivo.

Finite Element Analysis of Mechanics Property on Memory Alloy Patella Claws with Anti-Shearing Force

2014 ◽  
Vol 635-637 ◽  
pp. 507-510
Author(s):  
Dong Peng Du ◽  
Zhe Wu ◽  
Juan Xing ◽  
Xiao Yan Gong ◽  
Xiang Wen Miu ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Mechanical Performance ◽  
Tensile Force ◽  
Research Result ◽  
Element Model ◽  
3D Models ◽  
Shearing Force ◽  
Maximum Displacement ◽  
Element Analysis

When strong exercise on human being body, respectively, under knees 30°, 60°,90°, using PRO/E5.0 software to establish the transverse patella fracture and anti-shearing force patella claws 3D models, then the two structure models were assembled and imported into ABAQUS10.1 software to establish the finite element model of patellar fracture fixed within patella claw, and analyzed the mechanical performance in perforce finite element model. Under the same boundary conditions, the maximum displacement and deformation of each components were different at every flexion angle. Compared with anti-shearing force patella claw and AO tensile force girdle, the patella claw with stronger resistance to tension and anti-shearing force was more stable. Deformation and displacement of patella claw in accordance with biomechanical research result that is needed by clinical. Its stability will satisfy clinical requirements for functional exercise.

Airfoil Deformation Analysis During Stator Repair Process

2003 ◽  
Author(s):  
Shazia M. Alam ◽  
Mahdy Allam ◽  
Chittaranjan Sahay
Keyword(s):  
Finite Element ◽  
Coefficient Of Thermal Expansion ◽  
Repair Process ◽  
Deformation Analysis ◽  
Analysis Tool ◽  
Element Analysis ◽  
Jet Engine ◽  
Inconel Alloys ◽  
Before And After ◽  
History Of

The compressor stator assembly of a jet engine normally consists of stainless steel and Inconel alloys. Nickel based alloys can be also used as brazing material. Mechanical distortion of the stator assembly components may result during the brazing process. The coefficient of thermal expansion of the component materials, thermal history of manufacturing and operation also contribute to the stator deformation. The purpose of this work is to study the factors causing the distortion in vane stages. The study uses Finite Element Analysis tool ANSYS 5.7 for modeling the engine stator assembly. A finite element structural analysis of a single airfoil model is conducted at various repair points to assess the airfoil deformation and stress levels, before and after the brazing process. It is then used to identify materials and brazing parameters responsible for the observed distortion. The model analyzed shows general agreement between the numerical results and observations from the repair process. The probable causes of distortion are found and recommendations for fixing the distortion problem are also made.

Capacity Analysis of PE Pipeline With Non-Planar Defect

2013 ◽  
Author(s):  
Weijie Jiang ◽  
Jianping Zhao ◽  
Dingyue Chen
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Constitutive Model ◽  
Mechanical Performance ◽  
Orthogonal Design ◽  
Bending Moment ◽  
Limit Load ◽  
Capacity Analysis ◽  
Element Analysis ◽  
Load Factors

A tensile test of buried PE pipe is designed to test the mechanical performance. Then the constitutive model for the PE pipe can be established. The limit load of the PE pipe with local thinning defect can be studied with the method of combining the orthogonal design of experiment and finite element analysis. Then the factors of local thinning defect pipe limit load factors can be analyzed. The results show that the depth of the defect has a great effect on the limit load (internal pressure and bending moment) of PE pipe. The effects that the axial length of the defect and the circumferential length of the defect have on the limit load are not significant.

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