Integrated Dimensional Variation Analysis Method for Robust Process Design

2006 ◽  
Author(s):  
Bo Zhang ◽  
Francis E. Plonka
2019 ◽  
Vol 52 (3) ◽  
pp. 288-300 ◽  
Author(s):  
Linhan Ouyang ◽  
Jianxiong Chen ◽  
Yizhong Ma ◽  
Chanseok Park ◽  
Jionghua (Judy) Jin

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 455
Author(s):  
Nikolaos Boukis ◽  
I. Katharina Stoll

Gasification of organic matter under the conditions of supercritical water (T > 374 °C, p > 221 bar) is an allothermal, continuous flow process suitable to convert materials with high moisture content (<20 wt.% dry matter) into a combustible gas. The gasification of organic matter with water as a solvent offers several benefits, particularly the omission of an energy-intensive drying process. The reactions are fast, and mean residence times inside the reactor are consequently low (less than 5 min). However, there are still various challenges to be met. The combination of high temperature and pressure and the low concentration of organic matter require a robust process design. Additionally, the low value of the feed and the product predestinate the process for decentralized applications, which is a challenge for the economics of an application. The present contribution summarizes the experience gained during more than 10 years of operation of the first dedicated pilot plant for supercritical water gasification of biomass. The emphasis lies on highlighting the challenges in process design. In addition to some fundamental results gained from comparable laboratory plants, selected experimental results of the pilot plant “VERENA” (acronym for the German expression “experimental facility for the energetic exploitation of agricultural matter”) are presented.


2000 ◽  
Author(s):  
S. Jack Hu ◽  
Yufeng Long ◽  
Jaime Camelio

Abstract Assembly processes for compliant non-rigid parts are widely used in manufacturing automobiles, furniture, and electronic appliances. One of the major issues in the sheet metal assembly process is to control the dimensional variation of assemblies throughout the assembly line. This paper provides an overview of the recent development in variation analysis for compliant assembly. First, the unique characteristics of compliant assemblies are discussed. Then, various approaches to variation modeling for compliant assemblies are presented for single station and multi-station assembly lines. Finally, examples are given to demonstrate the applications of compliant assembly variation models.


2014 ◽  
Vol 800-801 ◽  
pp. 203-207
Author(s):  
Zhen Bo Wang ◽  
Liang Zhang ◽  
Shu Zhi Li

This article mainly aims at the problem of silicon carbide ceramic mechanical turning difficult processing,by adopting the method of the numerical control turning processing.Design a special fixtures and a NC machining process to accomplish the manufacture of silicon carbide plate.And through the single factor analysis method to process parameters were analyzed.


1999 ◽  
Author(s):  
Y. Zhang ◽  
X. Daniel Fang

Abstract A new measure for evaluating fit quality of mating parts via Fit Capability Indices (FCIs) is introduced as an interface between fit quality and process control of the mating parts. Fit Capability Analysis method is discussed based on the relationship between FCIs and Process Capability Indices (PCIs). A new statistical tolerancing approach for assuring predetermined fit quality is developed on the basis of fit quality evaluation measures and fit capability analysis, which can be used as a guideline to process design and process monitoring of the mating parts.


2019 ◽  
Vol 39 (1) ◽  
pp. 101-112 ◽  
Author(s):  
Biao Mei ◽  
Weidong Zhu ◽  
Yinglin Ke ◽  
Pengyu Zheng

Purpose Assembly variation analysis generally demands probability distributions of variation sources. However, due to small production volume in aircraft manufacturing, especially prototype manufacturing, the probability distributions are hard to obtain, and only the small-sample data of variation sources can be consulted. Thus, this paper aims to propose a variation analysis method driven by small-sample data for compliant aero-structure assembly. Design/methodology/approach First, a hybrid assembly variation model, integrating rigid effects with flexibility, is constructed based on the homogeneous transformation and elasticity mechanics. Then, the bootstrap approach is introduced to estimate a variation source based on small-sample data. The influences of bootstrap parameters on the estimation accuracy are analyzed to select suitable parameters for acceptable estimation performance. Finally, the process of assembly variation analysis driven by small-sample data is demonstrated. Findings A variation analysis method driven by small-sample data, considering both rigid effects and flexibility, is proposed for aero-structure assembly. The method provides a good complement to traditional variation analysis methods based on probability distributions of variation sources. Practical implications With the proposed method, even if probability distribution information of variation sources cannot be obtained, accurate estimation of the assembly variation could be achieved. The method is well suited for aircraft assembly, especially in the stage of prototype manufacturing. Originality/value A variation analysis method driven by small-sample data is proposed for aero-structure assembly, which can be extended to deal with other similar applications.


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