Tool Load Sensitivity Against Multidimensional Process Influences in Microblanking of Thin Metal Foils With Silicon Punches

2015 ◽  
Author(s):  
Sven Hildering ◽  
Markus Michalski ◽  
Ulf Engel ◽  
Marion Merklein
Keyword(s):  
Finite Element ◽  
Tool Life ◽  
Tool Material ◽  
Cutting Edge ◽  
Material Behavior ◽  
Transfer Of Knowledge ◽  
Test Rig ◽  
Element Analysis ◽  
Tensile Stresses ◽  
Process Behavior

The continuous trend towards miniaturization of metallic micro parts of high quality at low costs results in the need of appropriate production methods. Mechanical manufacturing processes like forming and blanking meet these demands. One major challenge for the application of them are so called size effects. Especially the downsizing of the required manufacturing tools and adequate positioning causes higher effort with increasing miniaturization. One promising approach for downsizing of tools is the transfer of knowledge from microsystems technology. This study shows the process behavior of etched silicon punches in microblanking operations. For the application as tool material especially the brittle material behavior and sensitivity against tensile stresses have to be considered. These mechanical loads favor wear in form of cracks and breaks at the cutting edge of the punch and decrease tool life. In a special test rig these wear phenomena were observed in microblanking of copper foils. Although high positioning accuracy between tools and workpiece can be assured within this test rig, scatter of tool life is observable. Therefore, a finite element analysis of the tool load in the microblanking process with special respect to tensile stresses was performed. Within the 3D finite element model multidimensional positioning errors like tilting between punch and die were integrated. Their influence on the tool load in form of increasing tensile stresses is evaluated with respect to the type and magnitude of positioning error. Furthermore, the effects of small outbreaks at the cutting edge on the process behavior and tool load are analyzed.

Tool Load Sensitivity Against Multidimensional Process Influences in Microblanking of Copper Foils With Silicon Punches

2016 ◽  
Vol 138 (9) ◽  
Author(s):  
Sven Hildering ◽  
Markus Michalski ◽  
Ulf Engel ◽  
Marion Merklein
Keyword(s):  
Tool Life ◽  
Tool Material ◽  
Cutting Edge ◽  
Material Behavior ◽  
Fe Model ◽  
Transfer Of Knowledge ◽  
Test Rig ◽  
Tensile Stresses ◽  
Copper Foils ◽  
Process Behavior

The continuous trend toward miniaturization of metallic microparts of high quality at low costs results in the need of appropriate production methods. Mechanical manufacturing processes like forming and blanking meet these demands. One major challenge for the application of them are the so-called size effects. Especially, the downsizing of the required manufacturing tools and adequate positioning cause higher effort with increasing miniaturization. One promising approach for downsizing of tools is the transfer of knowledge from microsystems technology. This study shows the process behavior of etched silicon punches in microblanking operations. For the application as tool material especially, the brittle material behavior and sensitivity against tensile stresses have to be considered. These mechanical loads favor wear in form of cracks and breaks at the cutting edge of the punch and thus decreasing tool life. In a special test rig these wear phenomena were observed in microblanking of copper foils. Although, high positioning accuracy between tools and workpiece can be assured within this test rig, scatter of tool life is observable. Therefore, a finite element (FE) analysis of the tool load in the microblanking process with special respect to tensile stresses was performed. Within the 3D FE model multidimensional positioning errors like tilting between punch and die were integrated. Their influence on the tool load in form of increasing tensile stresses is evaluated with respect to the type and magnitude of positioning error and verified by experimental results concerning wear. Furthermore, the effect of small outbreaks at the cutting edge on the process behavior and tool load is analyzed.

A Finite Element Analysis of the Human Temporomandibular Joint

1994 ◽  
Vol 116 (4) ◽  
pp. 401-407 ◽  
Author(s):  
J. Chen ◽  
Liangfeng Xu
Keyword(s):  
Finite Element ◽  
Temporomandibular Joint ◽  
Reaction Force ◽  
Element Model ◽  
Contact Stresses ◽  
Element Analysis ◽  
Tensile Stresses ◽  
Reaction Forces ◽  
Von Mises ◽  
Von Mises Stresses

A 2-D finite element model of the human temporomandibular joint (TMJ) has been developed to investigate the stresses and reaction forces within the joint during normal sagittal jaw closure. The mechanical parameters analyzed were maximum principal and von Mises stresses in the disk, the contact stresses on the condylar and temporal surfaces, and the condylar reactions. The model bypassed the complexity of estimating muscle forces by using measured joint motion as input. The model was evaluated by several tests. The results demonstrated that the resultant condylar reaction force was directed toward the posterior side of the eminence. The contact stresses along the condylar and temporal surfaces were not evenly distributed. Separations were found at both upper and lower boundaries. High tensile stresses were found at the upper boundaries. High tensile stresses were found at the upper boundary of the middle portion of the disk.

Finite Element Analysis of Casing Material Behavior in Steam Injection Well Operations

2015 ◽  
Vol 799-800 ◽  
pp. 196-200
Author(s):  
Abhilash M. Bharadwaj ◽  
Sonny Irawan ◽  
Saravanan Karuppanan ◽  
Mohamad Zaki bin Abdullah ◽  
Ismail bin Mohd Saaid
Keyword(s):  
Finite Element ◽  
Oil Recovery ◽  
Thermal Stresses ◽  
Oil And Gas ◽  
Extreme Temperature ◽  
Injection Pressure ◽  
Oil And Gas Industry ◽  
Steam Injection ◽  
Material Behavior ◽  
Element Analysis

Casing design is one of the most important parts of the well planning in the oil and gas industry. Various factors affecting the casing material needs to be considered by the drilling engineers. Wells partaking in thermal oil recovery processes undergo extreme temperature variation and this induces high thermal stresses in the casings. Therefore, forecasting the material behavior and checking for failure mechanisms becomes highly important. This paper uses Finite Element Methods to analyze the behavior two of the frequently used materials for casing - J55 and L80 steels. Modeling the casing and application of boundary conditions are performed through Ansys Workbench. Effect of steam injection pressure and temperature on the materials is presented in this work, indicating the possibilities of failure during heating cycle. The change in diameter of the casing body due to axial restriction is also presented. This paper aims to draw special attention towards the casing design in high temperature conditions of the well.

Creep Life Simulation and Assessment of High Temperature Piping Systems and Components

2012 ◽  
Author(s):  
Brian Rose ◽  
James Widrig
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Temperature ◽  
Creep Behavior ◽  
Material Behavior ◽  
Piping System ◽  
Remaining Life ◽  
Creep Life ◽  
Element Analysis ◽  
Piping Systems

High temperature piping systems and associated components, elbows and bellows in particular, are vulnerable to damage from creep. The creep behavior of the system is simulated using finite element analysis (FEA). Material behavior and damage is characterized using the MPC Omega law, which captures creep embrittlement. Elbow elements provide rapid yet accurate modeling of pinching of piping, which consumes a major portion of the creep life. The simulation is used to estimate the remaining life of the piping system, evaluate the adequacy of existing bellows and spring can supports and explore remediation options.

Nonlinear Finite Element Analysis for Thermoplastic Pipes

1998 ◽  
Vol 1624 (1) ◽  
pp. 225-230 ◽  
Author(s):  
Chuntao Zhang ◽  
Ian D. Moore
Keyword(s):  
Finite Element ◽  
Geometrical Nonlinearity ◽  
Constitutive Models ◽  
Material Behavior ◽  
Pipe Material ◽  
Limit States ◽  
Element Analysis ◽  
Finite Element Program ◽  
Highly Nonlinear ◽  
Nonlinear Constitutive Models

Thermoplastic pipes are being used increasingly for water supply lines, storm sewers, and leachate collection systems in landfills. To facilitate limit states design for buried polymer pipes, nonlinear constitutive models have recently been developed to characterize the highly nonlinear and time-dependent material behavior of high-density polyethylene (HDPE). These models have been implemented in a finite element program to permit structural analysis for buried HDPE pipes and to provide information regarding performance limits of the structures. Predictions of HDPE pipe response under parallel plate loading and hoop compression in a soil cell are reported and compared with pipe response measured in laboratory tests. Effects on the structural performance of pipe material nonlinearity, geometrical nonlinearity, and backfill soil properties were investigated. Good correlations were found between the finite element predictions and the experimental measurements. The models can be used to predict pipe response under many different load histories (not just relaxation or creep). Work is ongoing to develop nonlinear constitutive models for polyvinylchloride and polypropylene to extend the predictive capability of the finite element model to these materials.

Finite Element Analysis of a Locked Bolt With an Initial Crack

2009 ◽  
Author(s):  
Jean Paul Kabche ◽  
Mauri´cio Rangel Pacheco ◽  
Ivan Thesi ◽  
Luiz Carlos Largura
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Operating Conditions ◽  
Material Behavior ◽  
Isotropic Hardening ◽  
Stress Concentrations ◽  
Engineering Structures ◽  
Element Analysis ◽  
Micro Cracks ◽  
Non Linear

Bolted connections are largely employed in various types of engineering structures to transfer loads from one member to another. In particular, the off-shore industry has made extensive use of these connections, predominantly at the sub-sea level. In spite of their advantages, bolted joints are critical regions and may become sources of structural weakness due to large stress concentrations. Under severe operating conditions, micro-cracks can develop in the bolt, creating regions of elevated stress which may significantly reduce the integrity of the connection and ultimately lead to failure. This paper presents the three-dimensional finite element analysis of a steel locked bolt assembly aimed to assess the effect of micro-cracks on the structural integrity of the assembly using the commercial finite element package ANSYS. Non-linear contact between the bolt and nut threads is considered, where frictional sliding between components is allowed. A bi-linear isotropic hardening model is used to account for non-linear material behavior. The assembly is loaded by applying a pre-load of fifty percent of the yield stress of the material, according to the API-6A Norm. Two geometric models are investigated: a healthy locked bolt assembly with no initial cracks; and a damaged model, where a circular crack is introduced at the root of the bolt threads. The effect of the crack size is studied by modeling the crack with three different radius sizes. The J-Integral fracture mechanics methodology was used to study the stress concentrations in the damaged model.

Finite Element Modeling of Biodegradable Stents

2013 ◽  
Author(s):  
Nic Debusschere ◽  
Matthieu De Beule ◽  
Peter Dubruel ◽  
Patrick Segers ◽  
Benedict Verhegghe
Keyword(s):  
Finite Element ◽  
Mechanical Behavior ◽  
Mechanical Performance ◽  
Cost Effective ◽  
Minimal Invasive ◽  
Material Behavior ◽  
Element Analysis ◽  
Design And Optimization ◽  
Stent Restenosis ◽  
Biodegradable Stents

Biodegradable stents, which temporarily support a stenotic blood vessel and afterwards fully disappear, have recently gained a lot of interest. They avoid long-term complications associated with conventional stents such as late stent thrombosis and in-stent restenosis. Moreover, degradable stents allow for a restoration of vasomotion and vessel growth which makes them particularly suitable for pediatric applications [1]. Finite element simulations have proven to be an efficient and cost-effective tool to investigate and optimize the mechanical performance of minimal invasive devices such as stents [2]. Biodegradable stents have however created new challenges in their design and optimization via finite element analysis because of their complex time-varying material behavior. To correctly simulate the mechanical behavior of biodegradable stents, a model should be developed that incorporates the effect of degradation upon all material characteristics. By combining existing constitutive material models based on continuum damage theory we were able to create such a virtual environment in which the transitional mechanical behavior of biodegradable stents can be investigated.

Finite Element Based Automated Analysis for Determining Ratchet, Shakedown and Elastic Limits

2011 ◽  
Author(s):  
Jeries Abou-Hanna ◽  
Michael Paluszkiewicz
Keyword(s):  
Finite Element ◽  
Cyclic Load ◽  
Complex Geometry ◽  
Limit Load ◽  
Automated Analysis ◽  
Numerical Approach ◽  
Material Behavior ◽  
Element Analysis ◽  
Daunting Task ◽  
Elastic Shakedown

In order to determine the ratchet and shakedown limit curves for even a simple component, such as a tube under a constant pressure load and cyclic thermal load, can be a daunting task when using conventional analysis methods (elasto-plastic cyclic finite element analysis) that require repeated iterative simulations to determine the state of the structure, elastic, shakedown, plastic or ratchet. In some cases, the process is further complicated by the difficulty in interpreting results of the cyclic loading to determine in which regime the structure is. Earlier work by Abou-Hanna and McGreevy was able to demonstrate limit load analysis of a structure whose yield strength is modified based on cyclic load, provided the ratchet limit [1]. The method, called Anisotropic Load Dependent Yield Modification (LDYM), was implemented by using a user subroutine with ABAQUS, a general commercial finite element code. The approach adopted provided ratchet limits for only one individual cyclic load value. The work presented here describes a process for analyzing the structure and determining the elastic, shakedown and ratchet boundaries all in one finite element simulation using only one analysis step. The approach manipulates the structure material behavior that enables the resetting of the material characteristics to their original values in order to be able to analyze the structure for different sets of cyclic and primary load combinations. The process was verified using problems available in the literature, such as the Bree tube and Ponter’s Holed Plate. Additionally, a tubular T-joint was used as an example of the effectiveness of the process for a three dimensional complex geometry. The tubular T-joint results are verified against baseline data from the iterative elastic-plastic simulations used to determine the elastic, shakedown, and ratchet limits. The work presented highlights the advantages and limitations of this numerical approach which requires little interaction with the analyst.

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