Improving stripping efficiency of double curvature surface on a setup with turret head

The study was performed to develop a method for selecting a rational profile of a profiled flap wheel for a turret stripping head for cleaning parts with different radius of the transverse curvature. Researchers from the Irkutsk National Research Technical University and Irkutsk Aviation Plant designed and fabricated a special PFS-4 (peen forming setup) unit to implement manufacturing technology of large-scale contour-forming components. The unit is equipped with a CNC system, two movable operating elements, a shot blaster and a turret stripping head with four flap wheels. The paper offers methods and criteria for selecting the profiled flap wheel for stripping the contour-forming surfaces of the components, depending on the curvature radius of the latter. A flap wheel with an optimal curvature radius of 40 m was chosen for analysis, which allows a sufficiently large range of profile curvature of the processed components (from 8 to 40 m) to be covered. Profiled flap wheels 100 and 200 m wide with a flap profile radius of 40 m provided uniform material removal when cleaning the surface with a curvature radius from 8 to 40 m without further overlapping with a finished strip. It was shown that wider profiled flap wheels are necessary to increase stripping efficiency. In this case, a 300 mm wide flap wheel can be used for a component surface area with a transverse curvature radius over 14 m and a 400 mm wheel for surface areas with a curvature radius of over 20 m. Thus, comparing the stripping process of a curved surface by the straight flap wheel revealed that profiled flap wheels significantly expand the workability of the PFS-4 unit turret stripping head.

Download Full-text

Research on Motion Characteristics and Formation Mechanism of Debris Flow

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.711.388 ◽

2014 ◽

Vol 711 ◽

pp. 388-391

Author(s):

Ji Wei Xu ◽

Ming Dong Zhang ◽

Mao Sheng Zhang

Keyword(s):

Debris Flow ◽

Formation Mechanism ◽

Debris Flows ◽

Catchment Area ◽

Large Scale ◽

Large Range ◽

Extreme Rainfall ◽

Small Catchment ◽

Rainfall Characteristics ◽

Motion Characteristics

On July 9 2013, debris flows occurred around Longchi town with large scale and wide harm, which was a great threat to people's life and property as well as reconstruction work. Debris flow ditch in the surrounding town was studied. This paper focused on loose materials, topography and rainfall characteristics, and explored the formation mechanism of debris flow in Longchi town. The result shows that: a small catchment area in valleys also have the risk of large range of accumulation of debris flow, the debris flow is caused by a lot of loose materials in mountains after earthquake and extreme rainfall. Research results contribute to a better understanding of trigger condition of debris flow after earthquake.

Download Full-text

New Methods of Applying Rigid Agar Gels: From Tiny to Large-scale Surface Areas

Studies in Conservation ◽

10.1080/00393630.2020.1848272 ◽

2020 ◽

pp. 1-12

Author(s):

Ambra Giordano ◽

Paolo Cremonesi

Keyword(s):

Large Scale ◽

New Methods ◽

Surface Areas ◽

Agar Gels ◽

Scale Surface

Download Full-text

A cost effective approach to stormwater management? source control and distributed storage

Water Science & Technology ◽

10.2166/wst.1997.0684 ◽

1997 ◽

Vol 36 (8-9) ◽

pp. 307-311 ◽

Cited By ~ 8

Author(s):

R. Y. G. Andoh ◽

C. Declerck

Keyword(s):

Large Scale ◽

Traditional Approach ◽

Distributed Storage ◽

Cost Effective ◽

Source Control ◽

Slowing Down ◽

Surface Areas ◽

Cost Effective Approach ◽

Receiving Waters ◽

The Cost

Rapid urbanisation and its consequent increase in impermeable surface areas and changes in land use has generally resulted in problems of flooding and heavy pollution of urban streams and other receiving waters. This has often been coupled with ground water depletion and a threat to water resources. The first part of this paper presents an alternative drainage philosophy and strategy which mimics nature's way by slowing down (attenuating) the movement of urban runoff. This approach results in cost-effective, affordable and sustainable drainage schemes. The alternative strategy can be described as one of prevention rather than cure by effecting controls closer to source rather than the traditional approach which results in the transfer of problems downstream, resulting in its cumulation and the need for large scale, centralised control. The second part describes a research project which has been launched in order to quantify the cost and operational benefits of source control and distributed storage. Details of the methodology of the modelling and simulation processes which are being followed to achieve this target are presented.

Download Full-text

Wafer Scale Modeling and Control for Yield Improvement in Wafer Planarization

Microelectromechanical Systems ◽

10.1115/imece2002-33454 ◽

2002 ◽

Author(s):

Sutee Eamkajornsiri ◽

Ranga Narayanaswami ◽

Abhijit Chandra

Keyword(s):

Material Removal Rate ◽

Integrated Circuit ◽

Material Removal ◽

Large Scale ◽

Removal Rate ◽

Control Strategies ◽

Elastic Half Space ◽

Modeling And Control ◽

Planarization Process ◽

Curvature Control

Chemical mechanical polishing (CMP) is a planarization process that produces high quality surfaces both locally and globally. It is one of the key process steps during the fabrication of very large scale integrated (VLSI) chips in integrated circuit (IC) manufacturing. CMP consists of a chemical process and a mechanical process being performed together to reduce height variation across a wafer. High and reliable wafer yield, which is dependent upon uniformity of the material removal rate across the entire wafer, is of critical importance in the CMP process. In this paper, the variations in material removal rate (MRR) variation across the wafer are analytically modeled assumimg a rigid wafer and a flexible polishing pad. The wafer pad contact is modeled as the indentation of a rigid indenter on an elastic half-space. Load and curvature control strategies are investigated for improving the wafer yield. The notion of curvature control is entirely new and has not been addressed in the literature. The control strategy is based on minimizing a moment function that represents the wafer curvature and the height of the oxide layer left for material removal. Simulation results indicate that curvature control can improve wafer yield significantly, and is more effective than just the load control.

Download Full-text

Microbiological and Visual Effects of Trimming and/or Spray Washing for Removal of Fecal Material from Beef

Journal of Food Protection ◽

10.4315/0362-028x-58.9.984 ◽

1995 ◽

Vol 58 (9) ◽

pp. 984-989 ◽

Cited By ~ 28

Author(s):

BRENDA M. GORMAN ◽

J. BRAD MORGAN ◽

JOHN N. SOFOS ◽

GARY C. SMITH

Keyword(s):

Adipose Tissue ◽

Material Removal ◽

Fecal Material ◽

Microbiological Contamination ◽

Visual Effects ◽

Tissue Samples ◽

Surface Areas ◽

Plate Counts ◽

Subcutaneous Adipose ◽

Control Samples

Microbiological and visual evaluations were performed to compare the efficacy of hand trimming, spray washing, or a combination of treatments, in the removal of bacteria and fecal material from beef adipose tissue. Subcutaneous adipose samples with intact fascia from the surfaces of briskets (obtained within 15 min postmortem) were inoculated on different sizes of surface areas (0, 0.3125, 0,625, 1.25, 1.875, or 2.50 cm2) with a bovine fecal paste containing a culture of streptomycin-resistant Escherichia coli ATCC 11370. The samples were then spray washed with water at 35°C in a specially designed automated spray washing cabinet at pressures of 2.76, 13.79, 20.68, or 27.58 bar and at chain speeds equivalent to 100, 200, or 300 carcasses per hour (exposure times of 36, 18, or 12 s). Total aerobic mesophilic plate counts, streptomycin-resistant bacterial plate counts and visual scores for fecal contamination were obtained. There was a reduction (P < 0.05) in microbiological counts on the treated samples compared with those on the unwashed and/or untrimmed inoculated (control) samples. The variation in removal of fecal material from, and in reduction of microbiological contamination on, different sizes of surface areas of fecal material contamination and with different chain-speeds was minor under the conditions of the study. Hand trimming followed by spray washing compared to spray washing alone were similiar in their effectiveness for reduction of microbiological contamination and slightly different in the extent of fecal material removal. Overall, however, higher spray washing pressures (20.68 or 27.58 bar) were more effective (P < 0.05) than the lower spray washing pressures (2.76 or 13.79 bar) in removing fecal material from and reducing bacterial numbers on adipose tissue samples.

Download Full-text

The Contribution of Matrix Plasticity to the “Frictional” Sliding of Debonded Fibers in Sapphire-Reinforced TiAl Matrix Composites

MRS Proceedings ◽

10.1557/proc-350-143 ◽

1994 ◽

Vol 350 ◽

Author(s):

J. M. Galbraith ◽

D. A. Koss ◽

J. R. Hellmann

Keyword(s):

Material Removal ◽

Large Scale ◽

Tial Alloy ◽

Dominant Role ◽

Matrix Composites ◽

Matrix Interface ◽

Frictional Sliding ◽

Sic Fiber ◽

The Matrix ◽

Fiber Matrix Interface

AbstractLarge-scale fiber displacement behavior, usually characterized by a “frictional” sliding stress (τslide), has been studied in two sapphire-reinforced TiAl systems. Experimental results from fiber pushout and reverse push-back tests indicate that the large-scale sliding behavior of debonded fibers leads to an average τslide-value which progressively decreases during fiber displacements. Previous studies of SCS-6 (SiC) fiber-reinforced glass and metal matrix composites have attributed decreases in τslide to the fracture and wear of fiber asperities. However, given a matrix in which fiber asperities do not easily wear (e.g., a TiAl alloy), SEM examination of the fiber/matrix interface indicates that matrix plasticity plays a dominant role in the decrease of τslide with fiber displacement. Experimental evidence suggests that the observed decrease in τslide can be attributed to (1) a decrease in fiber roughness perceived by the matrix due to matrix grooving and (2) a relaxation of radial clamping as a result of material removal from the interface.

Download Full-text

Formulation of a three-dimensional shear-flexible bimaterial beam element with constant curvature

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406214563740 ◽

2014 ◽

Vol 229 (15) ◽

pp. 2687-2705 ◽

Cited By ~ 1

Author(s):

Eugenio Dragoni ◽

William J Bagaria

Keyword(s):

Large Scale ◽

Three Dimensional ◽

Beam Element ◽

Curvature Radius ◽

Test Case ◽

Torsional Stress ◽

Shear Forces ◽

Beam Curvature ◽

Numerical Predictions ◽

Curved Beam Element

This paper presents the closed-form formulation for a three-dimensional curved beam element with round bimaterial section. The formulation includes the effects of shear forces on displacements and stresses and of the beam curvature on the distribution of bending and torsional stress over the cross section. The element is coherent with the well-known theory for straight beams, which is obtained exactly as the curvature radius becomes infinite. The numerical predictions for a test case compare favourably with published analytical and experimental results and with the outcome of a purposely developed, large-scale FE brick model.

Download Full-text

System for In Vivo Nanoinjection of Tissues

Volume 4: 21st Design for Manufacturing and the Life Cycle Conference; 10th International Conference on Micro- and Nanosystems ◽

10.1115/detc2016-60033 ◽

2016 ◽

Author(s):

Talmage H. Jones ◽

Brian D. Jensen

Keyword(s):

Large Scale ◽

Genetic Material ◽

Injection System ◽

Radius Of Curvature ◽

Curvature Radius ◽

Convex Surfaces ◽

Preliminary Results ◽

Flexible Designs ◽

Micrometer Scale

This paper investigates the design of a nano-injection system that can deliver genetic material to cells within live tissue. The approach to creating such a system was to create candidate designs that meet all the requirements for successful in vivo injection and can be fabricated using silicon etching. The designs were tested through large-scale prototyping and through models that describe the systems’ behavior on the micrometer scale. One design consists of an array of lances on a rigid backing. The other design consists of an array of lances grouped in sets of three on a backing that can conform to the shape of the tissue being injected. Each design was prototyped in 3D printed ABS plastic. Preliminary results were qualitative and showed that the rigid and flexible designs performed similarly on mostly flat and irregular surfaces. On convex surfaces with a strong curvature (radius of curvature of about 2 cm), the flexible array gave slightly better results. Final testing gave a quantitative comparison of the two designs’ efficiencies on strongly curved convex surfaces. These results supported the preliminary results that the flexible array is more efficient in reaching points on the tissue than the rigid array is. As the applied force increased, each array performed more efficiently.

Download Full-text

Application of Processing Method Enlarging a Partial Diameter to Shaft Parts of Practical Size

Materials Science Forum ◽

10.4028/www.scientific.net/msf.475-479.3065 ◽

2005 ◽

Vol 475-479 ◽

pp. 3065-3070 ◽

Cited By ~ 2

Author(s):

Kazuki Mori ◽

Nagatoshi Okabe ◽

Xia Zhu ◽

Tadashi Iura

Keyword(s):

Compressive Stress ◽

Deformation Behavior ◽

Large Scale ◽

Processing Method ◽

Curvature Radius ◽

Bending Angle ◽

Round Bar ◽

Novel Processing ◽

Axial Compressive Stress ◽

Industrial Machine

. A novel processing method was proposed to enlarge a partial diameter in the middle of a round bar with an experimental size of 10mm in diameter. To confirm that the processing method is applicable also to shaft with a practical size of 25mm-60mm in diameter for general industrial machine, a large-scale processing machine was developed. Deformation behavior of diameter in a processed part during processing process was made to an expression. The several influences, such as bending angle θ, axial-compressive stress σc, diameters D0, rotation number N of shaft and curvature radius ρ, on the increase behavior of diameter were estimated quantitatively.

Download Full-text