Multifunctional Engineering Design of Elastomeric Components

2006 ◽  
Vol 79 (5) ◽  
pp. 881-891 ◽  
Author(s):  
Kenneth Reifsnider ◽  
Xinyu Huang ◽  
Yue Zou ◽  
Roham Solasi ◽  
Matthew Feshler
Keyword(s):  
Engineering Design ◽  
Constitutive Equations ◽  
Failure Criteria ◽  
Large Strains ◽  
Material Response ◽  
Active Stress ◽  
Stress States ◽  
Relationship Of ◽  
The Relationship ◽  
Mechanical Constraint

Abstract Earlier work has shown that the strength and growth of defects in elastomers is greatly affected by microstructure and mechanical constraint. Current work is focused on ionomeric materials which behave as elastomers under certain conditions of temperature, hydration, and mechanical constraint. These materials are typically characterized by large strains to failure. The present paper will deal with two aspects of their response that is important to design. The first is the creation of nonlinear constitutive equations that are appropriate for the description of their response in commercial codes. And the second is the development of strength concepts that are appropriate for the description of failure of such materials. Finally, the relationship of the material response and failure criteria to complexity of active stress states will be discussed.

scholarly journals Investigation on shear strain of reinforced concrete membrane panels subjected to pure shear

2019 ◽  
Vol 11 (8) ◽  
pp. 168781401986948
Author(s):  
Je-Pyong Jeong ◽  
Dae-Hung Kang
Keyword(s):  
Reinforced Concrete ◽  
Shear Strain ◽  
Pure Shear ◽  
Failure Criteria ◽  
Principal Compressive Stress ◽  
Strain Relationship ◽  
Trial And Error Method ◽  
Shear Strain Energy ◽  
Relationship Of ◽  
The Relationship

Hsu recently conducted a shear test on nine reinforced concrete panel elements subjected to applying pure shear using a shear testing device. Modern truss models (i.e. modified compression field theory and a rotating angle softened truss model) are used to perform a complex nonlinear analysis through a trial and error method based on a double loop. This analysis is conducted by employing equilibrium conditions, compatibility conditions, and a ductile stress–strain relationship of a reinforced concrete membrane panel in a biaxial state. In this study, an effective algorithm that uses a revised Mohr compatibility method based on the failure criteria of struts and ties is proposed. This algorithm is used to improve the convergence rate in the analysis of shear history, which was performed in the experiment of Hsu. The result of the analysis indicates that the shear strain energy in a state of extended shear strain is influenced by the relationship between principal compressive stress and strain (crushing failure).

Human Interaction in the Manufacturing Design Process

2000 ◽  
Vol 44 (12) ◽  
pp. 2-503-2-506 ◽  
Author(s):  
Robert L. Getty
Keyword(s):  
Engineering Design ◽  
Cost Effective ◽  
Human Interaction ◽  
Human Engineering ◽  
Fighter Aircraft ◽  
Human Element ◽  
Product Delivery ◽  
Relationship Of ◽  
Support Cost ◽  
The Relationship

The human element pervades all company processes, from proposal, design, manufacturing, quality control and product support. Cost effective processes can be best achieved when the human element is totally integrated with technology. Traditional human engineering design methodologies applied to company processes optimizes the relationship of people that comprise the organization with the technology that is the foundation of the organization. Process ownership is essential for the achievement of the goals of quality. This ownership occurs by applying macroergonomics precepts by integration of the personnel system with the technological factors to achieve product delivery to a satisfied customer within the external environment of market forces. The application of human engineering design principles will be discussed followed by the quality focus of the LMTAS company processes. This paper will review LMTAS quality goals to show the elements that form the foundation of The Fighter Enterprise to make it the contractor of choice for tactical fighter aircraft.

scholarly journals A Writing Kit for Engineering Design Reports

2010 ◽  
Author(s):  
Margaret Hundleby ◽  
Medhat Moussa ◽  
William David Lubitz ◽  
Peggy Pritchard
Keyword(s):  
Engineering Design ◽  
Design Work ◽  
Student Writers ◽  
Self Evaluation ◽  
Layered Approach ◽  
Page Design ◽  
The University ◽  
Relationship Of ◽  
The Relationship ◽  
Required Courses

Targeted writing instruction is introduced into a third year design course in a series of four required courses in engineering design at the University of Guelph. A variety of writing resources are gathered and adapted to the needs of students required to deliver a 40-page Design Report for a client-based project. The Writing Kit uses a multi-layered approach, including online and print resources and composing workshops explaining writing for analytic purposes, and makes rubrics available for self-evaluation by student writers. Instruction focuses on the relationship of written documentation to design work and the importance of outcomes for evaluating the success of the work as well as for producing it. The writing kits is available for download from the University of Guelph library repository http://atrium.lib.uoguelph.ca/

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

Studies on Leukemogenic and Sarcomagenic Viruses

1970 ◽  
Vol 28 ◽  
pp. 156-157
Author(s):  
Leon Dmochowski
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Morphological Properties ◽  
Mode Of Development ◽  
Relationship Of ◽  
The Relationship

Electron microscopy has proved to be an invaluable discipline in studies on the relationship of viruses to the origin of leukemia, sarcoma, and other types of tumors in animals and man. The successful cell-free transmission of leukemia and sarcoma in mice, rats, hamsters, and cats, interpreted as due to a virus or viruses, was proved to be due to a virus on the basis of electron microscope studies. These studies demonstrated that all the types of neoplasia in animals of the species examined are produced by a virus of certain characteristic morphological properties similar, if not identical, in the mode of development in all types of neoplasia in animals, as shown in Fig. 1.

The relationship of IGE receptor topography to signaling activity in RBL-2H3 mast cells

1991 ◽  
Vol 49 ◽  
pp. 236-237
Author(s):  
J.R. Pfeiffer ◽  
J.C. Seagrave ◽  
C. Wofsy ◽  
J.M. Oliver
Keyword(s):  
Mast Cells ◽  
Protein A ◽  
Scattered Electron ◽  
Ige Receptor ◽  
Receptor Complexes ◽  
Ige Binding ◽  
Electron Imaging ◽  
Small Clusters ◽  
Relationship Of ◽  
The Relationship

In RBL-2H3 rat leukemic mast cells, crosslinking IgE-receptor complexes with anti-IgE antibody leads to degranulation. Receptor crosslinking also stimulates the redistribution of receptors on the cell surface, a process that can be observed by labeling the anti-IgE with 15 nm protein A-gold particles as described in Stump et al. (1989), followed by back-scattered electron imaging (BEI) in the scanning electron microscope. We report that anti-IgE binding stimulates the redistribution of IgE-receptor complexes at 37“C from a dispersed topography (singlets and doublets; S/D) to distributions dominated sequentially by short chains, small clusters and large aggregates of crosslinked receptors. These patterns can be observed (Figure 1), quantified (Figure 2) and analyzed statistically. Cells incubated with 1 μg/ml anti-IgE, a concentration that stimulates maximum net secretion, redistribute receptors as far as chains and small clusters during a 15 min incubation period. At 3 and 10 μg/ml anti-IgE, net secretion is reduced and the majority of receptors redistribute rapidly into clusters and large aggregates.

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