Finite Element Contact Analysis Research Articles

Tooth contact analysis of a curvilinear gear set with modified pinion tooth geometry

This article investigated the contact behaviours of a modified curvilinear gear set for parallel-axis transmission, which exhibits a pre-designed parabolic transmission error (TE) and localized bearing contact. The proposed gear set is composed of a modified pinion with curvilinear teeth and an involute gear with curvilinear teeth. Tooth contact analysis enabled the authors to explore the influences of assembly errors and design parameters on TEs and contact ellipses of this gear set. It is observed that TEs were continuous and the contact ellipses were localized in the middle of the tooth flanks, even under assembly errors. Finite-element contact analysis was performed to study stress distributions under different design parameters. In addition, numerical examples are presented to demonstrate the contact characteristics of the modified curvilinear gear set.

Finite Element Analysis of Hybrid Ceramic Ball Bearing Contact

Because of its border nonlinearity, the contact between rolling element and ball race is difficult to be solved .With the development of computer technology and FEA theory, practical solution about contact is possible. This thesis which takes B7005C hybird ceramic ball bearing for example draws inner and outer contact stress and contact deformation and compares the results with Hertz solution by modeling, meshing, and setting contact pairs in ANSYS. The results show the use of ANSYS in bearing simulation is ideal, and can take a reference for the bearing simulation.

Contact Analysis for Joint Interfaces of Machine Tools Based on a 3-D Anisotropic Asperity Model

In this paper, a 3-D contact model for anisotropic rough surfaces based on 3-D statistically measurements is established and finite element contact analysis is conducted. The average height of the asperity (h), the average summit distances between two neighboring peaks of asperities (Sx and Sy) are selected as the characterized parameters of the rough surface. Finite element simulation results show that the normal contact pressure has an exponential relation with the normal deformation and an exact linear relationship between the normal deformation and the real contact pressure of the surfaces is obtained. At last, the normal contact stiffness of the joint interface is obtained empirically with the exponential relationship assumption.

J022044 半月板形態が膝関節軟骨の力学状態に及ぼす影響に関する数値解析([J02204]診療技術と臨床バイオメカニクス(4))

Human knee joints can support high levels of mechanical load for decades. The mechanical factor plays an important role in the development of osteoarthritis of the knee that interferes to daily life. It is recognized that the morphological change due to the injury or thinning of meniscus may influence the mechanical environment of the knee cartilage and meniscus. To investigate the effects of the thinning of meniscus three dimensional finite element models of two knee joints the normal one and the one with thinning of the meniscus were constructed from the medical images and the finite element contact analysis of the knee joint was carried out in the present study. The load condition during level walking was introduced in the analysis. The results show that the stress magnitude and the location with the highest contact stress in the tibial cartilage are different in the two models. The higher stress and larger deformation were observed in the knee joint with thinning of meniscus.

Thermal–mechanical optimization of a novel nanocomposite-film typed flip chip technology

The paper aims at optimization of the residual thermal–mechanical behaviors of a novel Flip Chip (FC) technology during and after the fabrication process. In this study, we first introduce the novel adhesive-typed FC packaging technology, consisting of a nanocomposite film for anisotropic electrical conduction and a nonconductive paste (NCP) for developing NCP joints. In the optimization work, the material and geometry properties and the bonding process parameters are considered as the design parameters, and the constraints on the residual behaviors and the design parameters are included. To deal with the multi-criteria design optimization problem, an effective metamodeling-based design optimization scheme is applied, which integrates parametric finite element (FE) analysis, a response surface methodology (RSM) and an updating scheme. Moreover, to assess the residual behaviors, a process-dependent simulation methodology that integrates both transient thermal and nonlinear contact FE analyses and a “death–birth” meshing scheme is carried out. The validity of the process-dependent FE simulation methodology is confirmed through experiment. Finally, two design practices are performed, and the calculated optimal designs are compared with each other and with the original design. It turns out that the present optimization methodology can be very effective and robust in seeking the optimal design of the FC technology with a better residual thermal–mechanical performance after the NCP bonding process.

Tooth Contact Analysis of the Double Circular Arc Tooth Spiral Bevel Gear

Tooth contact analysis is an effective tool for meshing analysis of the double circular arc profile spiral bevel gear (DCAPSBG), as well as the basis for loading tooth contact analysis and finite element analysis. Applying the principle of tooth contact analysis (TCA) and the tooth profile characteristic of the DCAPSBG, this paper introduced and discussed the key contents and method of TCA computer programming for numerical simulation analysis of the transmission meshing quality of DCAPSBG. The TCA program developed in this paper, which had been verified by real examples, provided an effective approach for the design of DCAPSBG.

Performance Research and Structure Optimize on Printing Cylinder Based on Finite Element Contact Analysis

This paper concerns printing cylinders of offset press. In addition to research mechanism of the printing pressure, the paper employs finite element analysis and distance-anti-calculating to simulate the status of contacted contacting-cylinders. Deflection curves in axial and circumferential and the 3D model on deflection of cylinder are get. The result shows that in printing course, under the influence of gravity and printing pressure, the flexural deformation of cylinder is caused in the axial direction. besides, while printing pressure is applied to circumferential different position of printing cylinder, because of complex sectional construction，circumferential deformation is also inconsistent, so printing pressure is distributed asymmetrically that printing pressure is not only no-uniform in axial, but also wave-like periods in circumferential. The paper optimizes cylinder structure and proposes a new cylinder with pterygoid stiffeners of heterogeneous distribution. Simulation results show that the circumferential flexural curve of the optimized cylinder is obviously smooth than the original one, and the flexural distortion of the circumferential location point corresponding decreases, which indicates the anti-bending stiffness of optimized cylinder is enhanced as well as the flexural deformation is reduced, and the value of the different circumferential position’s printing pressure tends to be uniform. The maldistribution of the circumferential position’s printing pressure is improved effectively, which contributed to the improvement of printing quality.

Frictional Characteristics of Ultra–Thin Polytetrafluoroethylene (PTFE) Films Deposited by Hot Filament–Chemical Vapor Deposition (HFCVD)

Frictional characteristics of polytetrafluoroethylene (PTFE) films deposited by a hot filament chemical vapor deposition (HFCVD) method on glass substrates was investigated. A universal micro-tribotester (UMT) was used in the ball-on-flat configuration to examine the effect of coefficient of friction (COF). The effects of normal force (2.5–15 N), sliding speed (1.4 × 10−3 to 14 mm/s) and film thickness (0.3, 1, 5, 10 μm) on the frictional behavior of the PTFE film were tested. Optical microscopy was used to examine the wear tracks of the PTFE films. In addition, durability of the PTFE films was examined by monitoring the change of COF in ball-on-disk tests. The COF values of the tested PTFE films were found to be in the range 0.03–0.18 depending on the measurement conditions. In particular, PTFE exhibits a low COF at slow speeds and high normal forces compared to a high COF at high speeds and small normal forces. Modified Hertzian contact equations and finite element analysis were used to analyze the indentation process. Comparison with the width of the experimental wear tracks indicates that the PTFE layer has a small contribution in carrying the normal load yet provides good protection against tangential forces.

Element Selection and Meshing in Finite Element Contact Analysis

Contact problem, which exists widely in mechanical engineering, civil engineering, manufacturing engineering, etc., is an extremely complicated nonlinear problem. It is usually solved by the finite element method. Unlike with the traditional finite element method, it is necessary to set up contact elements for the contact analysis. In the different types of contact elements, the Goodman joint elements, which cover the surface of contacted bodies with zero thickness, are widely used. However, there are some debates on the characteristics of the attached elements of the Goodman joint elements. For that this paper studies the type, matching, and meshing of the attached elements. The results from this paper would be helpful for the finite element contact analysis.

Finite Element Analysis for Tooth Profile Modification of Gear-Box of Tracklayer

The quasi-static contact finite element analysis of meshing gear of gear-box is computed by using MSC.Marc software, then transmission error and surface contact stress of meshing gear are computed in different tooth profile modification methods. Due to the large load fluctuation of tracklayer, the target of tooth profile modification is suggested, which is to minimize the peak value of tooth contact stress to the full, and not to increase the transmission error fluctuation of gear system.

The Non-Linear Contact Finite Element Analysis of Seal Structure on Large Scale Cutting Tube Machine

According to structural feature and seal requirement for large scale cutting tube machine, the non-standard rubber lip seal ring was self-designed. The nonlinear finite element contact analysis was utilized to model, calculate and optimize the structure of the lip seal ring, so as to improve the seal performance of the lip-shaped seal ring, and to determine the criterion for failure of seal performance of the lip seal ring, therefore to lay a foundation for the optimal design and performance research of the lip seal ring. According to the actual working pressure for the cutting tube machine, the stress and deformation for the lip seal ring were simulated. It has been testified by the practical use that the finite element analysis is correct. The method to optimal design of the seal structure with finite element analysis is feasible.

Finite element models for brush-debris interaction in road sweeping

In this paper, 2-D and 3-D finite element (FE) models for particle removal mechanisms are constructed to study the interaction between brush tines and debris in road sweeping processes. A 2-D contact FE analysis is first performed to analyse the contact behaviour between a flicking brush tine and an object to sweep. Using this model, the removal mechanisms are studied and analysed. Furthermore, the effect of brush penetration on debris removal is investigated. The 2-D sweeping model is extended to an accurate 3-D contact model, which overcomes some geometric errors in the 2-D model. From the results, it is suggested that the major removal mechanisms are a horizontal dragging force and a rolling moment generated by the external forces. It is also found that penetration has a positive contribution when it is relatively small in a non-sticky environment. Furthermore, in this environment, it is found that sweeping loads have a small effect on the removal process as either flicking tines or cutting tines can produce adequate removal loads.

Trabecular bone strains around a dental implant and associated micromotions—A micro-CT-based three-dimensional finite element study

The first objective of this computational study was to assess the strain magnitude and distribution within the three-dimensional (3D) trabecular bone structure around an osseointegrated dental implant loaded axially. The second objective was to investigate the relative micromotions between the implant and the surrounding bone. The work hypothesis adopted was that these virtual measurements would be a useful indicator of bone adaptation (resorption, homeostasis, formation). In order to reach these objectives, a μCT-based finite element model of an oral implant implanted into a Berkshire pig mandible was developed along with a robust software methodology. The finite element mesh of the 3D trabecular bone architecture was generated from the segmentation of μCT scans. The implant was meshed independently from its CAD file obtained from the manufacturer. The meshes of the implant and the bone sample were registered together in an integrated software environment. A series of non-linear contact finite element (FE) analyses considering an axial load applied to the top of the implant in combination with three sets of mechanical properties for the trabecular bone tissue was devised. Complex strain distribution patterns are reported and discussed. It was found that considering the Young’s modulus of the trabecular bone tissue to be 5, 10 and 15 GPa resulted in maximum peri-implant bone microstrains of about 3000, 2100 and 1400. These results indicate that, for the three sets of mechanical properties considered, the magnitude of maximum strain lies within an homeostatic range known to be sufficient to maintain/form bone. The corresponding micro-motions of the implant with respect to the bone microstructure were shown to be sufficiently low to prevent fibrous tissue formation and to favour long-term osseointegration.

0906 有限要素法接触解析による寛骨臼移動術の生体力学的評価(OS34-1:筋骨格系のモデリングとシミュレーション1)

0906 有限要素法接触解析による寛骨臼移動術の生体力学的評価(OS34-1:筋骨格系のモデリングとシミュレーション1)

A Finite Element Study of the Effect of Contact Forces Between an Implant-Retained Crown and its Adjacent Teeth on Bone Stresses

ABSTRACTMost of finite element (FE) models used to study single tooth dental implants consider only an isolated implant. It is of course more realistic to model also the adjacent teeth of the implant. However, including the adjacent teeth significantly increases the complexity of the model and necessitates the complex contact analysis. The main difference between the FE models with and without the adjacent teeth is that the model without the adjacent teeth cannot capture the effect of the contact forces that are transferred between the implant-retained crown and the adjacent teeth. In this study, the hypothesis that the contact forces are not important is verified by the FE contact analysis. Realistic 3D FE models of a mandible and a single tooth implant with and without adjacent teeth are constructed and analyzed. It is found from the results that the difference between the maximum bone stresses of the two models is very small when various loading directions are considered. The obtained results, therefore, indicate that the effect of contact forces between a dental implant and its adjacent teeth is not significant. Consequently, the adjacent teeth can be excluded from FE models if various loading directions are considered.

On the Thermal–Mechanical Behaviors of a Novel Nanowire-Based Anisotropic Conductive Film Technology

Extensive understanding and management of the thermal-mechanical characteristics of novel packaging designs during the bonding process are indispensable to the realization of the technologies. Thus, this paper attempts to explore the bonding process-induced thermal-mechanical behaviors of an advanced flip chip (FC) electronic packaging. FC packaging employs a novel anisotropic conductive film, which is a thin composite film composed of polymer matrix and thousands of millions of highly oriented, 1-D silver (Ag) nanowires on the scale of 200 nanometers in diameter. For carrying out the process simulation, a process-dependent finite element (FE) simulation methodology that integrates both thermal and nonlinear contact FE analyses and a special meshing scheme is applied. The material properties of the nanoscale Ag wires are first explored using molecular dynamics (MD) simulations. By the characterized material properties of the Ag nanowires, the effective material properties of the composite film are derived through two theoretical approaches: 1) the rule-of-mixture (ROM) technique and 2) the proposed FE method-based approach. The predicted results by these two approaches are extensively compared with each other to examine the feasibility of using the widely used ROM technique for such cases. In addition, the validity of the proposed process-dependent FE simulation methodology is also confirmed through three experiments: 1) micro-thermocouple measurement of temperature; 2) Twyman-Green Moire interferometry measurement of out-of-plane deformations; and 3) portable engineering Moire interferometry measurement of in-plane deformations. Throughout the investigation, the effectiveness of the novel interconnect technology is demonstrated. Good agreement with the experiments is also obtained. It is found that the technology may ensure good electrical performance and structural integrity, not only at room temperature but even at elevated temperature, based on its substantial contact stresses but minor peeling stresses on the bonding line, together with a moderate, process-induced warpage on the substrate.

Finite element analysis of contact induced adhesion failure in multilayer coatings with weak interfaces

Experimental work reveals that the Ag/ZnO interface in the multilayer solar control coatings is weakest and most likely to fail during contact. In this study, a cohesive zone model embedded in a finite element code was used to model delamination in multilayer stack consisting of ZnO/Ag/ZnO on glass during contact. It shows that delamination occurs at the upper ZnO/Ag interface during loading when penetration exceeds a critical value, while, the double pinned buckling delamination failure occurs at the lower Ag/ZnO interface during the unloading cycle. Furthermore, it reveals the model based on mechanism of lateral crack at interface yields reasonably accurate values of interfacial toughness when tensile stress induced delamination occurs during unloading.

Powder Static Pressure Distributing on Pyramidal Silo

Based on the assumptions of Janssen formula, the powder static pressure distribution is discussed and the analytical formulas are established. The relevant numerical study is fulfilled through finite element contact analysis. Through comparing the finite element analysis results with the analytical results, it shows that the analytical formulas have error. The reason is mainly that the special contact state formed by the special silo structure is not incarnated in the analytical formulas. Based on the finite element analysis result, the analytical results are amended to give the final formulas of contact pressure on the pyramidal silo. The formulas show that the contact pressure correlates with the attribute parameters such as silo material, loose material bulk density and internal friction angle, as well as the design parameters such as silo wall obliquity and silo height. The final formulas are programmed to implement pressure load by using ANSYS parametric design language. The load distribution graphs are consistent with the scatter diagram, and the loading languages have good generality and portability. The formulas can simplify relevant calculation, and may be regarded as a supplement of Janssen formula.

Development of a finite element contact analysis algorithm for charged‐hydrated soft tissues with large sliding

AbstractThis paper focuses on a finite element analysis of contact phenomena with large sliding between charged‐hydrated biological soft tissues, such as articular cartilages, based on the triphasic theory. The impenetrability constraint between the contacting bodies and the continuity of the interstitial fluid and ion phases at the contact surfaces are imposed by applying a Lagrange multiplier approach with the contact pressure, chemical potential of the fluid and electrochemical potentials of ions as Lagrange multipliers. A node‐to‐segment one‐pass approach is adopted to cope with large deformations and sliding between the contact surfaces. To pass the contact patch test, contact boundary integrations are performed on both the master and slave contact surfaces. On the other hand, the degrees of freedom of the multipliers at the master nodes are eliminated by projecting the master nodes onto the slave surface to avoid overconstraint. The effectiveness of the proposed algorithm is verified by a couple of numerical examples, in which continuous distributions of displacement, fluid flow, ionic molar flow and Lagrange multipliers on or across the contact surface are confirmed. Copyright © 2008 John Wiley & Sons, Ltd.

Wear behavior of diamond wheel for grinding optical connector ferrule — FEA and wear test —

The grinding characteristics and the wear behavior of diamond wheel for grinding the optical connector ferrule were investigated by finite element analysis (FEA) and wear test. FEA of contact between diamond wheel and ferrule shows that the subsurface damage area of ferrule is 13μm from the interface of abrasive particle and matrix. Fallout of abrasive particle is affected by the stress state at the interface. A 2-D finite element model was established to calculate the distribution of stress at the interface. As the result of FEA, fallout condition of abrasive was concerned with the ratio of the critical protrusion; the ratio of particle size is about 0.6. FE model was established to investigate the effects of the diamond concentration of wheel. The FEA result shows that the lower concentration of it has larger wear volume due to the small stress propagation. To investigate grinding performance, the pin-on-disc wear test was carried out for three types of concentrations 75%, 100% and 125%. Through the wear test, it was confirmed that the 75% wheel concentration has the highest amount of wear volume. This result shows good agreement with that of FEA. And 100% concentration by considering the grinding ratio of the wheel shows the best optimized result for the grinding performance.