Finite Element Upsetting Analysis of a Ring: An Incremental Solution to the Contact Problem

This paper describes the considerations employed in the finite element analysis of a relatively “short” support skirt on a hydrocarbon reactor vessel. The analysis is accomplished in accordance with ASME B&PV Code, Section VIII, Division 2 alternate rules in conjunction with the guidelines outlined in WRC Bulletin 429. This provides a sound basis for the classification of the calculated stress intensities. The support skirt is capable of sustaining the deadweight load in addition to resisting the effects of thermal displacements, wind loadings, overturning moments from external piping loads on the attached hydrocarbon reactor vessel, and friction between the skirt base plate and concrete foundation. The displacement and thermal boundary conditions are well defined and discussed in detail. The effects of multiple scenarios for the displacement boundary conditions are examined. The skirt design also employs a hot-box arrangement whereby the primary mode of heat transfer is by radiation. A discussion of the two-part analysis is included and details the interaction between the heat transfer analysis and the subsequent structural analysis. The heat transfer finite element analysis is utilized to determine the temperatures throughout the bottom of the vessel shell and head, as well as the integrally attached support skirt. Of prime importance during the analysis is the axial thermal gradient present in the skirt from the base plate up to and slightly beyond the skirt-to-shell junction. While the geometry of the subject vessel and skirt is best described as axisymmetric, the imposed loadings are a mixture of axisymmetric and non-axisymmetric. This combination lends itself to the judicious selection and utilization of the harmonic finite element and properly chosen Fourier series representation of the applied loads. Comparison of the thermally induced axial stress gradient results from the FEA to those obtained by the closed form beam-on-elastic-foundation are also tendered and discussed. Finally, recommendations are included for the design and analysis of critical support skirts for large, heavy-wall vessels.

In this paper the numerical implementation of two-scale modelling of bone microstructure is presented. The study is a part of long-term project on bone remodelling which drives bone microstructure change based directly on trabeculae surface energy. The proposed approach is based on a first-order computational homogenization technique. The coincidence of macro- and micro-model kinematics is done with the use of uniform displacement and traction boundary conditions. The computational homogenization procedure is driven by a self-prepared manager which is coded in Python. The computation on real bone structure (a piece of female Wistar rat bone) is performed as well.

The present paper is concerned with composites in which the constituent interfaces are weak in shear and therefore exhibit shear deformation associated with sliding. Thermomechanical loadings of such systems are considered which consist of homogeneous traction or displacement boundary conditions and a uniform temperature change on the outside surface of the composite. For binary systems with isotropic constituents, it is shown that the actual fields in the purely thermal problem can be uniquely determined from the solution of the purely mechanical problem. This correspondence relation is used to determine the effective thermal strain and stress tensors on the basis of the effective mechanical properties. For multi—phase systems with anisotropic constituents undergoing interface slip and separation, the theorem of virtual work is used to establish a similar relation between the effective thermal tensors and the mechanical concentration factors and constituent properties of the composite.

Buckling of extensible thermoelastic rods

Characterisation of the mechanical properties of pultruded fibre-reinforced polymer tube

To improve design accuracy and shorten its cycle, finite element method is adopted in the process of crane designing. The integrated finite element analysis model was established for the whole column jib crane using finite element analysis software ANSYS. A feasible computational model which reflects the actual structure was built and displacement boundary condition was determined reasonably. By using the symmetries of structure and load, neglecting the specific structure of bearing but reserving motion relationship between slewing jib spindle and column bearing chamber, the model is simplified logically. The slewing jib, which has great stress gradient, was separated into two parts while its interface was maintained for different density when meshing. The model calculation results are in very good agreement with actual conditions which provide a theory basis for optimal design of integrated structure of column jib crane and modeling for products with similar structure.

A side contact model of joint is proposed, which considers the horizontal distance distribution and side contact between the asperities on the contact surfaces. The Leica DCM3D microscope is applied to collect the profile data of the grinding surfaces. After analyzing the profile data by the statistical method, it is found that the horizontal distance distributions between asperities on the contact surfaces show an approximate normal distribution. Based on the discovery, a contact model of joint considering the horizontal distance distribution and side contact between asperities is established by statistical theory. The simulation results of the model show that the dimensionless tangential contact stiffness of joint is always lower than that of the GZQ model under the condition of the same dimensionless average distance of contact surfaces and P/T. When the standard deviation of horizontal distance between asperities decreases, both the dimensionless tangential contact stiffness of joint and the dimensionless normal contact stiffness increase. The finite element analysis and the modal experiment based on the contact model are carried out. It is found that the first three modal frequencies and modal shapes obtained from finite element analysis are in good agreement with those from the modal experiment, and compared with the modal frequencies from experiment, the modal frequencies from finite element analysis based on the model proposed in this paper show less error than those of finite element analysis based on the GZQ model. Therefore, this model proposed in this paper can more accurately predict the dynamic characteristics of joint.

Today, dental implantology represents a reliable technique for treating both partial and total edentulism. The fixation of dentures on dental implants can be achieved using various techniques, where the choice of a specific technique depends on the patient’s individual needs, the jawbone’s condition, and the prosthesis design. Currently, the two most common types of prosthetic abutment connections are cemented and screwed, each with its own set of advantages and disadvantages. This study aimed to analyze a novel Morse cone connection system between the prosthesis and implant using finite element analysis (FEA). The analysis of connection retention was conducted using three different approaches: analytical, in vitro, and FEA. Three-dimensional models were created for systems comprising an abutment, healing cap, and crown under three inclination conditions: 0°, 15°, and 30°. Using Ansys finite element software (R1 2023), the impact of the tilt on the system retention was examined. The FEA showed results comparable with the in vitro studies regarding the retention strength for an abutment cap system with a 4° taper, obtaining 66.6 N compared with the 68 N calculated in our in vitro study. The inclination of the abutment affected the system retention due to the hole made in the abutment’s surface, decreasing the contact area between components. The Morse cone prosthesis–implant connection system was found to be the most stable and efficient compared with threaded or cemented systems. The retention was influenced by factors such as the abutment conicity, insertion strength, and the contact surface between components.

We examined the flexural capacity of glue-laminated bamboo (GLB) beams made from Bambusa spinosa through experimental four-point bending tests and Finite Element Analysis (FEA) to evaluate mechanical performance, validate numerical models and develop moment capacity equations. We demonstrate that Bambusa spinosa meets structural requirements for engineered bamboo, with GLB100 and GLB125 achieving flexural strengths of 146.78 MPa and 130.66 MPa, respectively. An adhesive shear bond strength of 15.45 MPa ensured durability and structural integrity, while FEA predictions closely aligned with experimental results, confirming the accuracy of numerical modeling in structural analysis. This reinforces the viability of GLB beams as a sustainable alternative to traditional materials, contributing to reducing environmental impact in construction. Economic feasibility, building code limitations and standardization challenges are hindering widespread adoption, necessitating further research on optimizing lamination techniques, adhesive selection, and long-term durability under diverse environmental conditions. This will enhance the applicability of GLB beams in real-world structural designs. Our findings support the advancement of engineering standards for GLB beams, and promoting Bambusa spinosa as a high-strength, eco-friendly solution for sustainable construction. • Experimental and numerical methods were used to evaluate the flexural performance of GLB beams made from Bambusa blumeana . • The GLB beams exhibited high flexural strength, with peak values reaching up to 146.78 MPa under four-point bending tests. • Finite Element Analysis (FEA) results closely matched experimental findings, validating the model’s predictive accuracy. • A custom moment capacity equation was developed to improve design reliability for bamboo-based structural members. • Findings support the structural viability of GLB beams as sustainable alternatives to conventional materials like steel and concrete.

The paper describes a theoretical study of elastic-plastic adhesive contact of rough surfaces based on n-point asperity model and accurate finite element analysis (FEA) of elastic-plastic deformation of single asperity contact. The n-point asperity model developed by Hariri et al (2006) is integrated with the elastic-plastic model of . In this study an attempt is made to extend the work of by incorporating intermediate elastic-plastic regime of deformation. A large range of interference values ranging from fully elastic through elastic-plastic to fully plastic deformation of contacting asperities is considered. The effect of varying load and material parameters is analyzed in terms of well established adhesion index and plasticity index. A comparison between the present analysis with that of model shows significant difference in load–separation behaviour depending on combinations of mean separation, adhesion index and plasticity index.

This paper describes the considerations employed in the finite element analysis of a relatively “short” support skirt on a hydrocarbon reactor vessel. The analysis is accomplished in accordance with ASME B&PV Code, Section VIII, Division 2 alternate rules in conjunction with the guidelines outlined in WRC Bulletin 429. This provides a sound basis for the classification of the calculated stress intensities. The support skirt is capable of sustaining the deadweight load in addition to resisting the effects of thermal displacements, wind loadings, overturning moments from external piping loads on the attached hydrocarbon reactor vessel, and friction between the skirt base plate and concrete foundation. The displacement and thermal boundary conditions are well defined and discussed in detail. The effects of multiple scenarios for the displacement boundary conditions are examined. The skirt design also employs a hot-box arrangement whereby the primary mode of heat transfer is by radiation. A discussion of the two-part analysis is included and details the interaction between the heat transfer analysis and the subsequent structural analysis. The heat transfer finite element analysis is utilized to determine the temperatures throughout the bottom of the vessel shell and head, as well as the integrally attached support skirt. Of prime importance during the analysis is the axial thermal gradient present in the skirt from the base plate up to and slightly beyond the skirt-to-shell junction. While the geometry of the subject vessel and skirt is best described as axisymmetric, the imposed loadings are a mixture of axisymmetric and non-axisymmetric. This combination lends itself to the judicious selection and utilization of the harmonic finite element and properly chosen Fourier series representation of the applied loads. Comparison of the thermally induced axial stress gradient results from the FEA to those obtained by the closed form beam-on-elastic-foundation are also tendered and discussed. Finally, recommendations are included for the design and analysis of critical support skirts for large, heavy-wall vessels.

The detectability of contact surface damage is discussed using damaged surface models employing infrared thermography and finite element analysis. Temperature distribution measured by infrared thermography on a contact surface model with air layer is compared with that of calculated results obtained from finite element analysis. From the comparison it is concluded that thermographic measuring is applicable to fretting fatigue damage evaluation.

Finite element analysis of stress singularity in partial slip and gross sliding regimes in fretting wear

Isogeometric analysis (IGA) offers significant improvement in geometric accuracy over finite element analysis (FEA) by utilizing non-uniform rational B-spline (NURBS) basis functions, which allow a precise representation of complex geometries. Within the IGA framework, the robustness and efficiency of contact formulations can be further improved by refining contact surfaces using higher-order NURBS functions. This paper presents a contact surface enrichment strategy based on a varying-order NURBS discretization for three-dimensional (3D) frictional large deformation contact problems. The strategy enhances contact surface resolution, keeping the overall computational cost low by avoiding unnecessary refinement in non-contact regions. It also achieves better accuracy and efficiency in capturing complex contact behavior, making it a promising framework for solving general 3D frictional large deformation contact problems. A detailed algorithm is provided to facilitate user implementation. A comprehensive set of numerical examples is also presented to show the effectiveness of the strategy.

In this paper, a receding contact problem for an elastic layer resting on a half plane is considered. The layer is pressed by two rectangular stamps placed symmetrically. It is assumed that the contact surfaces are frictionless and only compressive traction can be transmitted through the contact surfaces. In addition the effect of body forces is neglected. Firstly, the problem is solved analytically based on theory of elasticity. In this solution, the problem is reduced into a system of singular integral equations in which half contact length and contact pressures are unknowns using boundary conditions and integral transform techniques. This system is solved numerically using Gauss-Jacobi integral formulation. Secondly, two dimensional finite element analysis of the problem is carried out using ANSYS. The dimensionless quantities for the contact length and the contact pressures are calculated under various stamp size, stamp position and material properties using both solutions. The analytic results are verified by comparison with finite element results.