The Investigation of Internal Turret Single Point Mooring Slip Ring Structure Design

As a key component of tunnel boring machines (TBMs), the disc cutter ring and its structural parameters are closely related to the TBM tunneling quality. Literature review shows that investigations on optimization design methods for cutter ring structure are seriously insufficient. Therefore, in this paper, a multiobjective optimization design model of structural parameters for disc cutter rings is developed based on the complex geological conditions and the corresponding cutter ring structure design requirements. The rock breaking capability, energy consumption, load-bearing capability, wear life, and wear uniformity of disc cutter are selected as the objectives, and the geometric structure of cutter rings, ultimate load-bearing capability, and cutterhead drive performance are determined as constraints. According to the characteristics of this model, a self-adaptive multipopulation genetic algorithm (SAMPGA) is utilized to solve the optimization problem, and the Fuzzy analytical hierarchy process (FAHP) is employed to calculate weight coefficients for multiple objectives. Finally, the applicability of the proposed method is demonstrated through a case study in a TBM project. The results indicated that the rock breaking performance and service life of the disc cutter are improved after optimization by using the proposed method. The utilization of SAMPGA effectively solves the premature local convergence problems during optimization. The geological adaptability should be considered in the cutter ring structure design, which can be realized by using the proposed method based on the suitable weight coefficients.

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Design and Analysis on Fan-Shape Four Pyramid Grid with Single Point Supporting

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.166-169.207 ◽

2012 ◽

Vol 166-169 ◽

pp. 207-210

Author(s):

Ke Li ◽

Jing Ji

Keyword(s):

Material Selection ◽

Single Point ◽

Canopy Structure ◽

Element Model ◽

Internal Force ◽

Structure Design ◽

Structural Deformation ◽

Grid Structure ◽

Shape Variable ◽

Selection Of

Combined with canopy structure design of a old-man university, this paper introduces the selection of scheme, material selection and Load value of fan-shape variable height four pyramid grid structure. Using the software ANSYS, finite element model of grid structure is established, and internal force and deformation of the members are got, the bearing capacity of the members and structural deformation are checked, finally design and construction for the node of members and the detail of structure are given, these can provide references for the design of similar engineering.

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Effect of Guard Ring Design and Properties of Inter-Layer Dielectric Film on Chip Reliability

Electronic and Photonic Packaging, Electrical Systems Design and Photonics, and Nanotechnology ◽

10.1115/imece2005-79081 ◽

2005 ◽

Author(s):

Farnaz Parhami ◽

Stephen Pan

Keyword(s):

Crack Propagation ◽

Integrated Circuit ◽

Semiconductor Industry ◽

Ring Structure ◽

Structure Design ◽

Point Of View ◽

Guard Ring ◽

Element Analysis ◽

Good Reliability ◽

Interlayer Dielectric

One of the common reliability problems in semiconductor industry is delamination of dielectric films used in the integrated circuit manufacturing process. Although these films have demonstrated good reliability performance in wafer form, once placed in different packages and undergo stress testing (e.g. pressure cooker test) they tend to crack and delaminate and lead to eventual reliability failure of the chip. The die guard ring can impact propagation of cracks that are initiated at the edge of the die into the active circuitry of the die. We designed several guard ring structures and performed finite element analysis to compare the potential of crack propagation for different guard ring designs. It is found that some features of the design do not affect stress intensity factor KI (potential of crack propagation). For long crack (3.75 um), structure A may reduce KI. But, structure B will increase KI. From fracture mechanics point of view, structure A may stop crack propagation toward die center. However, with structure B, the crack may still penetrate into the die. For short crack (1.25 um), effect of guard ring structure design is negligible. We have made experimental wafers using our wafer manufacturing processes to create structure A and B around the dice. Some wafers were made with film AA as interlayer dielectric and some with film BB as interlayer dielectric. SEM inspections validate our FEM models that structure A captures more cracks at the edge of the die and prevents its propagation into the die while structure B is less effective. We have shown that even with incorporation of structure B guard ring, film BB looses adhesion to other layers and delaminates upon exposure to humidity in pressure cooker test while film AA never delaminates.

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Algorithm for Compression Design Allowable Determination of Composite Laminates with Initial Delaminations

Machines ◽

10.3390/machines9120307 ◽

2021 ◽

Vol 9 (12) ◽

pp. 307

Author(s):

Jianchao Guo ◽

Yongbo Zhang ◽

Ke Chen

Keyword(s):

Composite Laminates ◽

Composite Structures ◽

Factor Model ◽

Single Point ◽

Economic Benefits ◽

Structure Design ◽

Aircraft Structures ◽

Accurate Design ◽

Depth Position

With the increasing demands for detailed design of composite aircraft structures, the method of covering all damages with low design allowables cannot meet the current requirements for aircraft structure design. Herein, this paper proposes a novel algorithm for design allowable determination of composite laminates by combining the damage distribution with damage factor model of design allowable, so as to provide different structures with more accurate design allowables based on their initial damages. For the composite laminates with initial delaminations, a model describing the effect of delamination size and depth position on the compression design allowable is developed and the compression design allowable of different aircraft structures are individually determined by employing abundant initial delamination statistics. Compared with the design allowable offered by the single-point method, the design allowable based on the initial damage can be increased by at least 5% to 20%, greatly improving the economic benefits of the aircraft structures and providing an important support for the damage tolerance design of the composite structures.

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Small Angle Electron Scattering From Vacuum Condensed Metallic Films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100101657 ◽

1968 ◽

Vol 26 ◽

pp. 380-381

Author(s):

J. Silcox ◽

R. H. Wade

Keyword(s):

Electron Scattering ◽

Small Angle ◽

Ring Structure ◽

Two Dimensional ◽

Metallic Films ◽

Micro Structure ◽

Angle Scattering ◽

The Fourier Transform ◽

Source Of Information ◽

Kinematical Theory

Recent work has drawn attention to the possibilities that small angle electron scattering offers as a source of information about the micro-structure of vacuum condensed films. In particular, this serves as a good detector of discontinuities within the films. A review of a kinematical theory describing the small angle scattering from a thin film composed of discrete particles packed close together will be presented. Such a model could be represented by a set of cylinders packed side by side in a two dimensional fluid-like array, the axis of the cylinders being normal to the film and the length of the cylinders becoming the thickness of the film. The Fourier transform of such an array can be regarded as a ring structure around the central beam in the plane of the film with the usual thickness transform in a direction normal to the film. The intensity profile across the ring structure is related to the radial distribution function of the spacing between cylinders.

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Immunoelectron microscope detection of C-type natriuretic peptide in normal human atrial tissue

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100147776 ◽

1993 ◽

Vol 51 ◽

pp. 388-389

Author(s):

Chi-Ming Wei ◽

Margaret Hukee ◽

Christopher G.A. McGregor ◽

John C. Burnett

Keyword(s):

Amino Acid ◽

Natriuretic Peptide ◽

Vascular Tone ◽

Cardiac Tissue ◽

Ring Structure ◽

Terminal Amino Acid ◽

Amino Acid Peptide ◽

Normal Human ◽

Terminal Amino ◽

The Brain

C-type natriuretic peptide (CNP) is a newly identified peptide that is structurally related to atrial (ANP) and brain natriuretic peptide (BNP). CNP exists as a 22-amino acid peptide and like ANP and BNP has a 17-amino acid ring formed by a disulfide bond. Unlike these two previously identified cardiac peptides, CNP lacks the COOH-terminal amino acid extension from the ring structure. ANP, BNP and CNP decrease cardiac preload, but unlike ANP and BNP, CNP is not natriuretic. While ANP and BNP have been localized to the heart, recent investigations have failed to detect CNP mRNA in the myocardium although small concentrations of CNP are detectable in the porcine myocardium. While originally localized to the brain, recent investigations have localized CNP to endothelial cells consistent with a paracrine role for CNP in the control of vascular tone. While CNP has been detected in cardiac tissue by radioimmunoassay, no studies have demonstrated CNP localization in normal human heart by immunoelectron microscopy.

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