Manufacturing variation modeling and process evaluation based on small displacement torsors and functional tolerance requirements

Tolerance analysis plays an important role in the stage of product design and has great influences on the product assembly quality and manufacturing costs. Two major methods are used for three-dimensional functional tolerance analysis, which are small displacement torsor and analysis line. A positioning mechanism with two parts is presented for tolerance accumulation calculation. Through the comparison of these two methods on computation processes and results, analysis line method can establish the explicit relationship between the functional requirement and the tolerances of the influential part, which allows finding the accumulation results in the worst-case and statistical conditions. However, it requires the determination of transfer relationship case by case. For small displacement torsor model, it permits a set of inequalities to express the tolerance zones, which yields a linear programming problem. It is applicable to different tolerance chains for its general characteristic. However it is adopted only for the worst-case analysis and requires more computation time.

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Evaluation of Manufacturing Process based on the Geometric Variation Model in Multi-station Machining Processes

E3S Web of Conferences ◽

10.1051/e3sconf/202123103004 ◽

2021 ◽

Vol 231 ◽

pp. 03004

Author(s):

Heping Peng ◽

Zhuoqun Peng

Keyword(s):

Machine Tool ◽

Manufacturing Process ◽

Evaluation Method ◽

Cutting Tools ◽

Small Displacement ◽

Machining Processes ◽

Contact Surfaces ◽

Geometric Variation ◽

Manufacturing Variation ◽

Variation Model

The objective of this paper is to explore the evaluation method of manufacturing process to verify its effectiveness based on the limitation of the variations which occur in multi-station machining processes. Firstly, the manufacturing process of a mechanical part is considered as a mechanism mainly consisted of machine-tool, part-holders, machined part, and cutting tools; And small displacement torsors (SDTs) are applied to describe all deviations in the manufacturing process, including the variation deviations of the machined surfaces of a part with regards to their nominal positions, the gap deviations associated to each joint between two contact surfaces, etc; Then, the 3D manufacturing variation model is established based on the relations between the machining feature variations and the functional tolerance requirements to realize the evaluation of manufacturing process. Finally, an application example is given to illustrate the proposed method.

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Some applications of electron beam microanalysis techniques in VLSI process evaluation

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010007463x ◽

1983 ◽

Vol 41 ◽

pp. 160-161

Author(s):

Simon Thomas

Keyword(s):

Integrated Circuits ◽

Process Evaluation ◽

Large Scale ◽

Technology Development ◽

Analytical Techniques ◽

Successful Implementation ◽

Analysis Of Failures ◽

Characterization Of Materials ◽

Circuits Vlsi

Trends in the technology development of very large scale integrated circuits (VLSI) have been in the direction of higher density of components with smaller dimensions. The scaling down of device dimensions has been not only laterally but also in depth. Such efforts in miniaturization bring with them new developments in materials and processing. Successful implementation of these efforts is, to a large extent, dependent on the proper understanding of the material properties, process technologies and reliability issues, through adequate analytical studies. The analytical instrumentation technology has, fortunately, kept pace with the basic requirements of devices with lateral dimensions in the micron/ submicron range and depths of the order of nonometers. Often, newer analytical techniques have emerged or the more conventional techniques have been adapted to meet the more stringent requirements. As such, a variety of analytical techniques are available today to aid an analyst in the efforts of VLSI process evaluation. Generally such analytical efforts are divided into the characterization of materials, evaluation of processing steps and the analysis of failures.

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A Device for Magnification Measurement

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100096369 ◽

1972 ◽

Vol 30 ◽

pp. 622-623

Author(s):

J.A. Eades ◽

A. van Dun

Keyword(s):

Electron Microscope ◽

Small Displacement ◽

Private Communication ◽

Piezoelectric Crystal ◽

Double Exposure ◽

Standard Methods ◽

Elegant Method ◽

The Right ◽

Piezo Electric

The measurement of magnification in the electron microscope is always troublesome especially when a goniometer stage is in use, since there can be wide variations from calibrated values. One elegant method (L.M.Brown, private communication) of avoiding the difficulties of standard methods would be to fit a device which displaces the specimen a small but known distance and recording the displacement by a double exposure. Such a device would obviate the need for changing the specimen and guarantee that the magnification was measured under precisely the conditions used.Such a small displacement could be produced by any suitable transducer mounted in one of the specimen translation mechanisms. In the present case a piezoelectric crystal was used. Modern synthetic piezo electric ceramics readily give reproducible displacements in the right range for quite modest voltages (for example: Joyce and Wilson, 1969).

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Observation of faint contrast at planar faults in alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100108842 ◽

1978 ◽

Vol 36 (1) ◽

pp. 340-341

Author(s):

K. Kuroda ◽

Y. Tomokiyo ◽

T. Kumano ◽

T. Eguchi

Keyword(s):

Reciprocal Lattice ◽

Beam Theory ◽

Al Alloys ◽

Small Displacement ◽

Electron Microscopic ◽

Lattice Vector ◽

Fringe Contrast ◽

Planar Fault ◽

Lattice Displacement ◽

The Many

The contrast in electron microscopic images of planar faults in a crystal is characterized by a phase factor , where is the reciprocal lattice vector of the operating reflection, and the lattice displacement due to the fault under consideration. Within the two-beam theory a planar fault with an integer value of is invisible, but a detectable contrast is expected when the many-beam dynamical effect is not negligibly small. A weak fringe contrast is also expected when differs slightly from an integer owing to an additional small displacement of the lattice across the fault. These faint contrasts are termed as many-beam contrasts in the former case, and as ε fringe contrasts in the latter. In the present work stacking faults in Cu-Al alloys and antiphase boundaries (APB) in CuZn, FeCo and Fe-Al alloys were observed under such conditions as mentioned above, and the results were compared with the image profiles of the faults calculated in the systematic ten-beam approximation.

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Superstructures and ordering phenomena in ceramic superconductors

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100166014 ◽

1996 ◽

Vol 54 ◽

pp. 710-711

Author(s):

R. Gronsky

Keyword(s):

Domain Growth ◽

Small Displacement ◽

Small Scale ◽

Ceramic Superconductors ◽

Oxygen Sublattices ◽

Tweed Contrast ◽

Diffraction Patterns ◽

Representative Image ◽

Static Lattice ◽

Modulation Wavelength

It is now well established that the phase transformation behavior of YBa2Cu3O6+δ is significantly influenced by matrix strain effects, as evidenced by the formation of accommodation twins, the occurrence of diffuse scattering in diffraction patterns, the appearance of tweed contrast in electron micrographs, and the generation of displacive modulation superstructures, all of which have been successfully modeled via simple Monte Carlo simulations. The model is based upon a static lattice formulation with two types of excitations, one of which is a change in oxygen occupancy, and the other a small displacement of both the copper and oxygen sublattices. Results of these simulations show that a displacive superstructure forms very rapidly in a morphology of finely textured domains, followed by domain growth and a more sharply defined modulation wavelength, ultimately evolving into a strong <110> tweed with 5 nm to 7 nm period. What is new about these findings is the revelation that both the small-scale deformation superstructures and coarser tweed morphologies can result from displacive modulations in ordered YBa2Cu3O6+δ and need not be restricted to domain coarsening of the disordered phase. Figures 1 and 2 show a representative image and diffraction pattern for fully-ordered (δ = 1) YBa2Cu3O6+δ associated with a long-period <110> modulation.

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Counseling Adolescents With Hearing Loss Using a Narrative Therapy Approach

Perspectives on Administration and Supervision ◽

10.1044/aas19.2.72 ◽

2009 ◽

Vol 19 (2) ◽

pp. 72-78

Author(s):

Rebecca L. Nelson Crowell ◽

Julie Hanenburg ◽

Amy Gilbertson

Keyword(s):

Hearing Loss ◽

Process Evaluation ◽

Narrative Therapy ◽

Daily Life ◽

Hearing Aid ◽

Self Esteem ◽

Therapy Approach ◽

Self Worth ◽

Counseling Adolescents

Abstract Audiologists have a responsibility to counsel patients with auditory concerns on methods to manage the inherent challenges associated with hearing loss at every point in the process: evaluation, hearing aid fitting, and follow-up visits. Adolescents with hearing loss struggle with the typical developmental challenges along with communicative challenges that can erode one's self-esteem and self-worth. The feeling of “not being connected” to peers can result in feelings of isolation and depression. This article advocates the use of a Narrative Therapy approach to counseling adolescents with hearing loss. Adolescents with hearing loss often have problem-saturated narratives regarding various components of their daily life, friendships, amplification, academics, etc. Audiologists can work with adolescents with hearing loss to deconstruct the problem-saturated narratives and rebuild the narratives into a more empowering message. As the adolescent retells their positive narrative, they are likely to experience increased self-esteem and self-worth.

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