Finite Element Analysis on Temperature Field of Laser Brazing

2011 ◽  
Vol 295-297 ◽  
pp. 1428-1432
Author(s):  
Zhi Bo Yang ◽  
Li Mei Zhang ◽  
Peng Fei Luo ◽  
Jiu Hua Xu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Temperature Field ◽  
Surface Temperature ◽  
Material Properties ◽  
Processing Parameters ◽  
Temperature Dependent ◽  
Laser Brazing ◽  
Element Analysis ◽  
Fem Model

The purpose of this paper is used Ansys to simulate the temperature field of laser brazing by FEM. The 3-D solid elements are used in FEM model, and nonlinear factors of temperature-dependent material properties are considered. The surface temperature grades have been attained, and the brazing experiment have been conducted, the results show that the wetting of Ni-Cr alloy to diamond is good. This study is useful for selecting reasonable processing parameters on laser brazing.

Thermal Modeling of a Railroad Tapered-Roller Bearing Using Finite Element Analysis

2012 ◽  
Vol 4 (3) ◽  
Author(s):  
Constantine M. Tarawneh ◽  
Arturo A. Fuentes ◽  
Javier A. Kypuros ◽  
Lariza A. Navarro ◽  
Andrei G. Vaipan ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Surface Temperature ◽  
Elevated Temperatures ◽  
Roller Bearing ◽  
Fe Model ◽  
Element Analysis ◽  
Tapered Roller Bearing ◽  
Outer Race ◽  
Railroad Industry

In the railroad industry, distressed bearings in service are primarily identified using wayside hot-box detectors (HBDs). Current technology has expanded the role of these detectors to monitor bearings that appear to “warm trend” relative to the average temperatures of the remainder of bearings on the train. Several bearings set-out for trending and classified as nonverified, meaning no discernible damage, revealed that a common feature was discoloration of rollers within a cone (inner race) assembly. Subsequent laboratory experiments were performed to determine a minimum temperature and environment necessary to reproduce these discolorations and concluded that the discoloration is most likely due to roller temperatures greater than 232 °C (450 °F) for periods of at least 4 h. The latter finding sparked several discussions and speculations in the railroad industry as to whether it is possible to have rollers reaching such elevated temperatures without heating the bearing cup (outer race) to a temperature significant enough to trigger the HBDs. With this motivation, and based on previous experimental and analytical work, a thermal finite element analysis (FEA) of a railroad bearing pressed onto an axle was conducted using ALGOR 20.3™. The finite element (FE) model was used to simulate different heating scenarios with the purpose of obtaining the temperatures of internal components of the bearing assembly, as well as the heat generation rates and the bearing cup surface temperature. The results showed that, even though some rollers can reach unsafe operating temperatures, the bearing cup surface temperature does not exhibit levels that would trigger HBD alarms.

scholarly journals On the Design of a Biodegradable POC-HA Polymeric Cardiovascular Stent

2012 ◽  
Author(s):  
Joonas Ponkala ◽  
Mohsin Rizwan ◽  
Panos S. Shiakolas
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Material Properties ◽  
Three Dimensional ◽  
Polymeric Composite ◽  
Coronary Stent ◽  
Element Analysis ◽  
Material Models ◽  
Solid Models ◽  
Biodegradable Stents

The current state of the art in coronary stent technology, tubular structures used to keep the lumen open, is mainly populated by metallic stents coated with certain drugs to increase biocompatibility, even though experimental biodegradable stents have appeared in the horizon. Biodegradable polymeric stent design necessitates accurate characterization of time dependent polymer material properties and mechanical behavior for analysis and optimization. This manuscript presents the process for evaluating material properties for biodegradable biocompatible polymeric composite poly(diol citrate) hydroxyapatite (POC-HA), approaches for identifying material models and three dimensional solid models for finite element analysis and fabrication of a stent. The developed material models were utilized in a nonlinear finite element analysis to evaluate the suitability of the POC-HA material for coronary stent application. In addition, the advantages of using femtosecond laser machining to fabricate the POC-HA stent are discussed showing a machined stent. The methodology presented with additional steps can be applied in the development of a biocompatible and biodegradable polymeric stents.

Warpage Simulation During Fan-Out Wafer-Level Packaging Process with Uncertainty of Material Properties

2021 ◽  
Vol 21 (5) ◽  
pp. 2987-2991
Author(s):  
Geumtaek Kim ◽  
Daeil Kwon
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Material Properties ◽  
Coefficient Of Thermal Expansion ◽  
Input Output ◽  
Wafer Level ◽  
High Input ◽  
Element Analysis ◽  
Packaging Process ◽  
Wafer Level Packaging

Along with the reduction in semiconductor chip size and enhanced performance of electronic devices, high input/output density is a desired factor in the electronics industry. To satisfy the high input/output density, fan-out wafer-level packaging has attracted significant attention. While fan-out wafer-level packaging has several advantages, such as lower thickness and better thermal resistance, warpage is one of the major challenges of the fan-out wafer-level packaging process to be minimized. There have been many studies investigating the effects of material properties and package design on warpage using finite element analysis. Current warpage simulations using finite element analysis have been routinely conducted with deterministic input parameters, although the parameter values are uncertain from the manufacturing point of view. This assumption may lead to a gap between the simulation and the field results. This paper presents an uncertainty analysis of wafer warpage in fan-out wafer-level packaging by using finite element analysis. Coefficient of thermal expansion of silicon is considered as a parameter with uncertainty. The warpage and the von Mises stress are calculated and compared with and without uncertainty.

Damage Length Predictor for High-Speed Craft

1999 ◽  
Vol 36 (04) ◽  
pp. 203-210
Author(s):  
Steven P. McGee ◽  
Armin Troesch ◽  
Nickolas Vlahopoulos
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Material Properties ◽  
High Speed ◽  
Historical Data ◽  
Element Analysis ◽  
Damage Prediction ◽  
Structural Layout ◽  
Vessel Speed ◽  
Indenter Geometry

In 1994 the International Maritime Organization adopted the Code of Safety for High-Speed Craft (HSC Code). After two years of use, several shortfalls were found, one being the damage length predictor, which is based on traditional steel, mono-hulled vessels. Other damage predictors were developed based on historical data, but they do not account for variables such as aluminum or fiberglass construction, transverse members, indenter geometry variation, or for the case where the vessel comes to rest on the grounding object. This paper proposes a damage prediction model based on material properties, structural layout, grounding object geometry, and vessel speed. The model incorporates four grounding mechanisms: plate cutting, plate tearing, crushing of plate behind transverse members, and transverse member failure. The method is used to determine the resistance energy, compared to the kinetic energy, of the vessel, to determine an effective damage length. Finite-element analysis was used to model the failure of both aluminum and steel transverse members with significant differences in the results. It was found that the transverse members provided the majority of the resistance energy in one grounding mechanism and negligible resistance energy in another.

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