Front solution for finite element techniques

Front solution for finite element techniques

Abstracts of c.a.d, literature Aeronautical engineering Civil and structural engineering Control engineering Hague, D. S. and Glatt C.R. 73. 99 'In...

132KB Sizes 0 Downloads 104 Views

Abstracts of c.a.d, literature Aeronautical engineering

Civil and structural engineering

Control engineering

Hague, D. S. and Glatt C.R. 73. 99 'Integration of aerospace vehicle performance and design optimization' Atmospheric Flight Mecb., AIAA 2rid Conference, Palo Alto, California, (1 l t h 13th September 1972), 18pp Areas of performance optimization include boosters,re-entry vehicles and aircraft. The effect of very large scale vehicle design optimization codes on computer program design and computer operating system requirements is discussed.

Hellen, T. K. 73.103 'Front solution for finite element techniques' Central Electricity Generating Board, Berkeley, UK (October 1969), 29pp The front solution technique used in the SAFE general stress analysis system is described. The front solution is a computer algorithm for solving a large set of simultaneous equations which are of a banded nature. Important savings in computer time are effected by using Gaussian elimination.

Chart, H. C. and Perkins, W.R. 73.108 'Optimization of time delay systems using parameter imbedding' 5th World Congress on Automation held in Paris 1 2 t h - 1 7 t h June 1972. Presentation of a new computational approach for optimization of linear timedelay systems with quadratic indices. The method uses parameter imbedding and transforms the advanced delayed type two point boundary value form of necessary conditions to a sequence of conventional non-delayed linear boundary value problems.

Jacobs, H.G. 73.100 'Engineering optimization m e t h o d with application to STOL-aircraft approach and landing trajectories' National Aeronautics and Space Admin, Washington DC, USA (September 1972), 40pp The optimal open loop inputs for a dynamical system are computed by observing only its output. The inputs are expressed as a series of functions with parameters to be optimized and the method reduces to static optimization. The r e p o r t explains the method used and applies it to optimizing longitudinal landing paths for a STOL aircraft with an augmented wing. Wallace, R . E . 73.101 'Computerized system for the preliminary design of commercial airplanes' Boeing Company, Commercial Aircraft Division, Washington, USA (1972), 12pp The Boeing Co have developed a computerized preliminary design system for subsonic and transonic aeroplanes. The disciplines of aerodynamics, configuration design, flight controls, propulsion, structures and weights are interrelated with a versatile computer superstructure capable of solving a wide range of aeroplane synthesis problems. The libraries of technology modules, executive routines and machine systems routines can be automatically compiled into interactive, overlay-structured computer programs. Typical results of aeroplane design trade studies and configuration optimization are presented.

Chemical engineering Alonso, J. R.F. 73.102 'Dynamic programming formulation of the generalised multistage problem' Process Technology Vol 17, No 12 (December 1972), pp 935--939 The paper has four parts. 1. It performs a specification analysis for the generalised multi-component vapour-liquid contact stage; 2. Derives the equilibrium, material and energy balance equations in their most general form, independent o f the source of equilibrium and enthalpy data; 3. An analysis of the solution space resulting from the equations and finally; 4. Analysis o f the computational and practical implications of the solution space.

1 94

Majowiecki, M. 73.104 'A suspension structure for the Fiat agency at San Giovanni in Persiceto, Bologna (Italy)' Steel Vol 37 (December 1972) No 12, pp 497--502 The paper describes the design and construction of a building of contemporary character. Structural loadings are calculated by computer. The program used second difference methods for solving a set of equations representing the problem.

Rand, R. A. and Shen, C.N. 73.105 'Optimum design of composite shells subject to natural frequency constraints' Compact. and Struct. Vol 3, No 2 (March 1973) pp 2 4 7 - 2 6 3 The optimization problem is posed as a general mathematical programming problem in which one or more of the inequality constraints involves the shell natural frequencies, which must be evaluated numerically during the optimization. The method is based on the finite element method and Rayleigh's principle. The unconstrained minimizations are performed by using the variable matrix method of Fletcher and Powell.

Touma, A. and Wilson J . F . 73.106 'Design optimization of prestressed concrete spans for high speed ground transportation' Comput. and Struct., Vol 3, No 2 (March 1973), pp 2 6 5 - 2 7 9 A computer program is described for the calculation of optimum geometric configurations of prestressed concrete girders with nonlinear constraint conditions involving stresses and deflections. The program uses the direct search method. Several numerical results for simple spans are included.

Viswanathau, A. V., Soong, T.C. 73. 107 and Miller, R. E. 'Compressive buckling analysis and design of stiffened flat plates with multilayered composite reinforcement' Comput. and Struct., Vol 3, No 2 (March 1973) pp 281--297 An analysis and its application in design is given for the compressive buckling of flat stiffened plates considered as an assemblage of linked orthotropic flat plate and beam elements.

Gilles, G. and Nougaret, M. 73.109 'Optimal control of a pilot heat exchanger' 5th World Congress on Automation, held in Paris 1 2 t h - 1 7 t h June, 1972 First part o f paper gives a practical method for synthesizing industrial control systems. Second part describes a mathematical model for a pilot heat-exchanger. Mayne, D . Q . 73.110 'The design of linear multivariable systems' 5th World Congress on Automation, held in Paris 1 2 t h - 1 7 t h June, 1972 A c.a.d, procedure is described whereby a succession of single-loop designs,using Nyquist loci, yield a multivariable design which is stable and strongly attenuates disturbances. The procedure permits more freedom than previously available for the choice of compensating matrix. Munro, N. 73.111 'Computer-aided design procedure for reduced order observers' Proc, Inst. IEE Vol 120 (February 1973) No 2 pp 319--324 The author presents a systematic design procedure for reduced-order observers for linear time-invariant dynamical systems described by state space equations. The procedure uses an alternative canonical form to that considered by Luenberger. The algorithm developed is suitable for the case where an estimate of the entire state vector is required and can be extended to the case where only an estimate of a single linear functional of the state is needed. The procedure deals with the c.a.d, of reduced-order observers which will re-construct an estimate of the entire state vector. An example illustrates the procedure. Murali, B. N. et al 73.112 'Optimization of constrained dynamic systems using the sequential unconstrained minimization technique' Trans. of the ASME J. of Dynamic Systems, Measurement and Control, Vol 94, Series G No 4 (December 1972), pp 319--322

Pedersen, J. O., P4hner, F. and 73.113 Solheim, O. A. 'Computer aided design of multivariable control systems' 5th World Congress on Automation, held in Paris 1 2 t h - 1 7 t h June 1972

COMPUTER AIDED DESIGN