The Optimum Shape


Book Description

This book contains the papers presented at the International Symposium, "The Optimum Shape: Automated Structural Design," held at the General Motors Research Laboratories on September 3D-October 1, 1985. This was the 30th symposium in a series which the Research Laboratories began sponsoring in 1957. Each symposium has focused on a topic that is both under active study at the Research Laboratories and is also of interest to the larger technical community. While attempts to produce a structure which performs a certain task with the minimum amount of resources probably predates recorded civilization, the idea of coupling formal optimization techniques with computer-based structural analysis techniques was first proposed in the early 1960s. Although it was recognized at this time that the most fundamental description of the problem would be in terms of the shape or contours of the structure, much of the early work described the problem in terms of structural sizing parameters instead of geometrical descriptions. Within the past few years, several research groups have started to explore this more fundamental area of shape design. Initial research has raised many new questions about appropriate selection of design variables, methods of calculating derivatives, and generation of the underlying analysis problem.




Optimum Shape for Transpiration-cooled Nosetip of a Re-entry Vehicle


Book Description

The variations of parameters method was used to determine the optimum nose shape for a reentry vehicle having a transpiration-cooled nosetip (TCNT). Three families of nose shapes were considered - The oblate ellipsoid, the flat face - round shoulder, and the spherical arc - round shoulder. These families are bounded by the flat face - sharp corner at one extreme and the hemisphere at the other extreme. The amount of coolant required by each nose shape during reentry was determined by using a high speed computer to couple the aerodynamic equations with the trajectory equations. The optimum shape is the shape which requires the least amount of coolant for reentry. The flat face - sharp corner shape was found to require the least amount of coolant, about 60 percent less water than the hemisphere. Although the time to impact is longer for the flat face, the smaller surface area and lower heating intensity more than offsets the increased reentry time. The possibility of an optimum flat face height was also investigated; no face height was found that minimized the total heating to the vehicle during reentry. (Author).




Large Engineering Systems


Book Description

Large Engineering Systems documents the proceedings of the International Symposium held at the University of Manitoba, Canada on August 9-12, 1976. This book compiles papers on the technology of large engineering systems. The topics discussed include the analysis of an automobile body by finite element method; finite-element solution of boundary integral equations; optimum design of stiffened plate girders; and tuning of miniaturized analog hybrid circuits. The sparsity in large systems and trans-shipment problems; finite difference method with graded lattices; Kron's multidimensional electromagnetic networks; and analyses of large systems are also deliberated. This text likewise covers the transient phenomena in large electrical power systems; modeling for regional electric power supply system; and efficient method for reliability evaluation of large-scale systems. This publication is a good source for engineers who intend to acquire knowledge on large-scale engineering systems.




Advanced Studies Of Flexible Robotic Manipulators: Modeling, Design, Control And Applications


Book Description

Flexible robotic manipulators pose various challenges in research as compared to rigid robotic manipulators, ranging from system design, structural optimization, and construction to modeling, sensing, and control. Although significant progress has been made in many aspects over the last one-and-a-half decades, many issues are not resolved yet, and simple, effective, and reliable controls of flexible manipulators still remain an open quest. Clearly, further efforts and results in this area will contribute significantly to robotics (particularly automation) as well as its application and education in general control engineering. To accelerate this process, the leading experts in this important area present in this book the state of the art in advanced studies of the design, modeling, control and applications of flexible manipulators.




Analysis and Optimization of Prismatic and Axisymmetric Shell Structures


Book Description

Shell-type structures can be found almost everywhere. They appear in natural forms but also as man-made, load-bearing components in diverse engineering systems. Mankind has struggled to replicate nature’s optimization of such structures but using modern computational tools it is now possible to analyse, design and optimise them systematically. Analysis and Optimization of Prismatic and Axisymmetric Shell Structures features: comprehensive coverage of the background theory of shell structures; development and implementation of reliable, creative and efficient computational tools for static and free-vibration analysis and structural optimization of variable-thickness shells and folded-plate structures; integrated computer-aided curve and surface modelling tools and automatic mesh generation, structural analysis sensitivity analysis and mathematical programming methods; well-documented, downloadable Fortran software for these techniques using finite element and finite strip simulations which can be readily adapted by the reader for the solution of practical problems or for use within a teaching or research environment. Written by leading experts in finite element and finite strip methods, Analysis and Optimization of Prismatic and Axisymmetric Shell Structures will be of great interest to researchers in structural mechanics and in automotive, aerospace and civil engineering as well as to designers from all fields using shell structures for their strength-per-unit-mass advantages.




Proceedings of the 5th International Conference on Jets, Wakes and Separated Flows (ICJWSF2015)


Book Description

This volume collects various contributions from the 5th International Conference on Jets, Wakes and Separated Flows (ICJWSF2015) that took place in Stockholm during June 2015. Researchers from all around the world presented their latest results concerning fundamental and applied aspects of fluid dynamics. With its general character, the conference embraced many aspects of fluid dynamics, such as shear flows, multiphase flows and vortex flows, for instance. The structure of the present book reflects the variety of topics treated within the conference i.e. Jets, Wakes, Separated flows, Vehicle aerodynamics, Wall-bounded and confined flows, Noise, Turbomachinery flows, Multiphase and reacting flows, Vortex dynamics, Energy-related flows and a section dedicated to Numerical analyses.




Hypersonic Inviscid Flow


Book Description

Unified, self-contained view of nonequilibrium effects, body geometries, and similitudes available in hypersonic flow and thin shock layer; appropriate for graduate-level courses in hypersonic flow theory. 1966 edition.




NASA Technical Paper


Book Description




Tribology of Machine Elements


Book Description

Tribology is a branch of science that deals with machine elements and their friction, wear, and lubrication. Tribology of Machine Elements - Fundamentals and Applications presents the fundamentals of tribology, with chapters on its applications in engines, metal forming, seals, blasting, sintering, laser texture, biomaterials, and grinding.




Control of Boundaries and Stabilization


Book Description

The present proceedings volume is devoted to two subjects. Stabilization with emphasis on exact controllability: considering a physical system, such as a vibrating plate, one can reach a steady state in a finite time by acting on the boundary. Control of boundaries: given a physical system find the geometry of the domain (optimal shape) which minimizes a cost related to the solution of a boundary value problem in this domain, for example find a minimum drag profile. Many lectures included mathematical analysis as well as engineering applications and numerical simulation.