scholarly journals Modeling and Characterization for Microstrip Filters in the Manufacturing Process through the Unscented Transform and Use of Electromagnetic Simulators

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Abraham E. Ortega Paredes ◽  
Leonardo R. A. X. de Menezes ◽  
Humberto Abdalla ◽  
Ivan N. A. Romani
Keyword(s):  
Manufacturing Process ◽  
Uncertainty Modeling ◽  
Design Stage ◽  
Microwave Devices ◽  
Unscented Transform ◽  
Electromagnetic Simulations ◽  
Passive Devices ◽  
Microstrip Filters ◽  
Different Types ◽  
Manufacturing Tolerances

This paper presents the unscented transform (UT) applied to uncertainty modeling of manufacturing tolerances at the design stage of microwave passive devices. The process combines the UT with electromagnetic simulations and assumes that the numerical sources of error are negligible in comparison to the imperfections due to the manufacturing process. The technique was validated with the simulation, construction, and test of several sets of identical microstrip filters with very good results. Although the combination of UT and electromagnetic simulators was presented for microstrip filters, it can also be used for different types of microwave devices.

Quantifying Design and Manufacturing Robustness Through Stochastic Optimization Techniques

1996 ◽  
Author(s):  
David Kazmer ◽  
Philip Barkan ◽  
Kosuke Ishii
Keyword(s):  
Manufacturing Process ◽  
Process Variation ◽  
Optimization Techniques ◽  
Design Stage ◽  
Tool Geometry ◽  
Detailed Design ◽  
Process Dynamics ◽  
Molded Parts ◽  
Industry Practice ◽  
End Use

Abstract Critical design decisions are often made during the detailed design stage assuming known material and process behavior. However, in net shape manufacturing processes such as stamping, injection molding, and metals casting, the final part properties depend upon the specific tool geometry, material properties, and process dynamics encountered during production. As such, the end-use performance can not be accurately known in the detailed design stage. Moreover, slight random variations during manufacture can inadvertently result in inferior or unacceptable product performance and reduced production yields. These characteristics make it difficult for the designer to select the tooling, material, and processing details which will deliver the desired functional properties, let alone achieve a robust design which is tolerant to process variation. This paper describes a methodology for assessing the design/manufacturing robustness of candidate designs at the detailed design stage. In the design evaluation, the fundamental sources of variation are explicitly modeled and the effects conveyed through the manufacturing process to predict the distribution of end-use part properties. This is accomplished by utilizing optimization of manufacturing process variables within Monte Carlo simulation of stochastic process variation, which effectively parallels the industry practice of tuning and optimizing the process once the tool reaches the production floor. The resulting estimates can be used to evaluate the robustness of the candidate design relative to the product requirements and provide guidance for design and process modifications before tool steel is cut, as demonstrated by the application of the methodology for dimensional control of injection molded parts.

Influence of imperfections on the stiffness of regular scaffold structures

2016 ◽  
Vol 232 (6) ◽  
pp. 453-464
Author(s):  
Ainhoa Martinez Ormaetxea ◽  
Andreas Öchsner
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Programming Language ◽  
Manufacturing Process ◽  
Experimental Testing ◽  
Bone Scaffold ◽  
Finite Element Software ◽  
Different Types ◽  
Data Files ◽  
Load Conditions

The manufacturing process of bone scaffold structures has an important influence on the final mechanical strength of the structure. When the structures are not produced properly, i.e. have imperfections such as missing parts or slightly displaced joints, they lose some of their mechanical properties. The aim of this study was to see how different types of damage affect the structures and also if their effects are equal when the structure is subjected to different load conditions. The change of the mechanical behavior was determined using the commercial finite element software MSC Marc Mentat. In turn, the damage was introduced by manipulating the structure’s files (ASCII data files) using the programming language Fortran. Apart from the numerical simulations, experimental testing was also performed to verify the numerical results. In the frame of this study, useful information for further research is provided.

Modeling and Representation of Manufacturing Knowledge for DFM Systems

2004 ◽  
Author(s):  
Zuozhi Zhao ◽  
Jami Shah
Keyword(s):  
Process Planning ◽  
Cost Estimation ◽  
Manufacturing Process ◽  
Feature Recognition ◽  
Design For Manufacturing ◽  
Time Cost ◽  
Computational Framework ◽  
Different Types ◽  
Manufacturing Knowledge ◽  
Manufacturing Time

The manufacturing knowledge today spans a vast spectrum, from manufacturing process capability/constraint, precedence, algorithms/heuristics of performing feature recognition, process planning and manufacturing time/cost estimation, to Design for Manufacturing (DfM) tactics and strategies. In this paper, different types of manufacturing knowledge have been identified and the ways to represent and apply them are described. An information model is developed as the backbone to integrate other existing tools into the framework. A computational framework is presented to help the manufacturing knowledge engineers formulize their knowledge and store it into the computer, and help the designers systematically analyze the manufacturability of the design.

The Influence of Elevated Temperature in Creep Relaxation of Various PTFE Gaskets Production Methods

2018 ◽  
Author(s):  
Ana C. Silva ◽  
Florian Werner ◽  
Lucas Xavier
Keyword(s):  
Manufacturing Process ◽  
Mechanical Characteristics ◽  
Elevated Temperatures ◽  
Impact Resistance ◽  
Relaxation Property ◽  
Production Method ◽  
Low Friction ◽  
Production Methods ◽  
Wide Range ◽  
Different Types

Polytetrafluoroethylene (PTFE) products have been widely used for industrial sealing applications due to their outstanding chemical resistance as well as their electrical, anti-stick, impact resistance and low friction properties. Diverse PTFE flat gaskets production methods are available in the industry, which include the combination of a selected Resin Type and a determined manufacturing process, being able to provide a wide range of several types of PTFE gaskets, with different mechanical characteristics. The production method has significant impact on the mechanical properties of the PTFE gaskets, especially the creep relaxation property at elevated temperatures. Therefore, the gasket behavior at high temperatures and, consequently, the bolted flanged joint (BFJ) performance, directly depends on both selected Resin Type and gasket manufacturing process. One of the most used PTFE gasket types is produced from multiaxially expanded PTFE sheets. As it is known, different types of stretching, among other factors, confer to the gasket particular mechanical characteristics. This type of gasket exhibits a very low gasket seating stress, and it is the preferred type for most low bolt load flanges. This paper presents a study of the creep relaxation property at room and elevated temperatures of expanded PTFE gaskets manufactured by different Resin Types and processes of expanding PTFE materials. Experimental results are presented comparing EN 13555 [1] Qsmax, PQR and ΔeGc parameters of the produced PTFE gaskets.

OPTIMIZATION OF PARAMETRIC YIELD: A TUTORIAL

1992 ◽  
Vol 03 (01) ◽  
pp. 95-136 ◽  
Author(s):  
STEPHEN W. DIRECTOR ◽  
PETER FELDMANN ◽  
KANNAN KRISHNA
Keyword(s):  
Manufacturing Process ◽  
Yield Loss ◽  
The Other ◽  
Parametric Yield ◽  
Other Hand ◽  
Different Types

Yield loss can be characterized as either catastrophic or parametric. Catastrophic yield loss is primarily due to local disturbances, such as spot defects, that occur in a manufacturing process. On the other hand, parametric yield loss is due to global disturbances, such as mask misalignment. In this paper we briefly explore these two different types of yield loss and then review some methods that have been developed to maximize parametric yield.

Comparison of Effects of Dimensional Manufacturing Tolerances and Journal Out-of-Roundness on Stability of Hydrodynamic Journal Bearing System

2011 ◽  
Vol 121-126 ◽  
pp. 1966-1971
Author(s):  
Wu Bin Xu ◽  
De Jian Zhou ◽  
Peter Ogrodnik ◽  
Mike Goodwin
Keyword(s):  
Theoretical Analysis ◽  
Taguchi Method ◽  
Journal Bearing ◽  
Journal Bearings ◽  
System Stability ◽  
Design Stage ◽  
Analysis Method ◽  
Manufacturing Tolerances ◽  
Hydrodynamic Journal Bearing ◽  
Bearing System

The manufacturing tolerances of a hydrodynamic journal bearing system are inevitable in manufacturing process. To examine and understand the effect of manufacturing tolerances on the system stability can help engineers to confidently choose reasonable tolerances at design stage. This study presented a theoretical analysis method to determine and compare the effects of dimensional manufacturing tolerances and journal out-of-roundness on system stability by Taguchi method. The results show that the journal out-of-roundness has the most significant effect on the system stability and the journal out-of-roundness appears to stabilize the system. The authors suggest that both dimensional manufacturing tolerances and journal roundness should be taken into account in the design of cylindrical journal bearings.

Design Optimization of Off-Chip Inductors

2003 ◽  
Author(s):  
Lin Jin ◽  
Albert Chee W. Lu ◽  
Lai L. Wai ◽  
Wei Fan ◽  
Aik Chong Tan ◽  
...  
Keyword(s):  
Design Optimization ◽  
Manufacturing Process ◽  
Design Methodology ◽  
Solution Space ◽  
Operating Frequency ◽  
Wafer Level ◽  
Space Design ◽  
Electromagnetic Simulations

A solution space design methodology is presented for optimization of off-chip inductors. The analysis has been performed for an advanced wafer level redistribution manufacturing process. Electromagnetic simulations were performed to extract the characteristics of different inductor designs. It was observed that the design optimization should be tuned to the operating frequency.

Experimental Study on the Injected Anchors Behaviour on Historical Masonry

2010 ◽  
Vol 133-134 ◽  
pp. 423-428 ◽  
Author(s):  
Cristiano Algeri ◽  
Elena Poverello ◽  
Giovanni Plizzari ◽  
Ezio Giuriani
Keyword(s):  
National Standard ◽  
Design Stage ◽  
Preliminary Design ◽  
Structural Interventions ◽  
In Situ Tests ◽  
Different Types ◽  
Preliminary Design Stage ◽  
Historical Masonry ◽  
Real Strength

The proposed paper reports the results of a research on the behaviour of injected anchors in historical masonry. The purpose of this investigation was to develop a methodology to be used as a preliminary design stage for structural interventions in order to pre-qualify the real strength of this kind of anchors. Several preliminary tests in laboratory with test specimens made of concrete and masonry and a first series of in situ tests on different types of masonry were conducted to analyse the behaviour of the anchorage and of the mortar. As this test is not included in National Standard, the studied standardised methodology could be adopted as a Guideline.

scholarly journals DYNAMICS BETWEEN ORDER AND CHAOS IN A SIMPLE REENTRANT MODEL OF PRODUCTION DYNAMICS

2003 ◽  
Vol 13 (05) ◽  
pp. 1343-1351 ◽  
Author(s):  
I. KATZORKE ◽  
A. PIKOVSKY
Keyword(s):  
Autocorrelation Function ◽  
Manufacturing Process ◽  
Processing Times ◽  
Different Types ◽  
One Machine ◽  
Production Dynamics

We consider a simple reentrant model of a manufacturing process, consisting of one machine at which two different types of items have to be processed. The model is completely deterministic: all delivery and processing times are fixed, and are generally incommensurate. Dependent on the arrival and processing times, a queue of waiting items grows, remains constant or disappears. We demonstrate that the dynamics of the system crucially depends on the queue type. Complexity is most observed for the case of growing queue. We characterize this dynamics between order and chaos with the T-entropy and the autocorrelation function.

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