The Solution and Parameter Analysis of the Single Pile Response Subject to Lateral Load Based on Three-Parameter Subgrade Resisting Force Model

To further investigate the mechanism of the interaction between the response of single pile and pile-soil on the condition of lateral load, on the basis of the normal type of the coefficient of subgrade reaction, this paper reaches the transfer matrix solution of single pile subject to lateral load by combining matrix transfer method with finite element method assuming that the coefficient of subgrade reaction is constant in each finite element. With the matrix solutions obtained, a computer program is developed using MATLAB to compute the pile responses and parametric studies are carried out on the effect of the constraint conditions of pile head and tip, effect of soil properties etc. and the results are discussed in detail.

A Rapid Approach for Calculating the Damped Eigenvalues of a Gas Turbine on a Minicomputer: Theory

The calculation of the damped eigenvalues of a large multistation gas turbine by the complex matrix transfer procedure may encounter numerical difficulties, even on a large computer due to numerical round-off errors. In this paper, a procedure is presented in which the damped eigenvalues may be rapidly and accurately calculated on a minicomputer with accuracy which rivals that of a mainframe computer using the matrix transfer method. The method presented in this paper is based upon the use of constrained normal modes plus the rigid body modes in order to generate the characteristic polynomial of the system. The constrained undamped modes, using the matrix transfer process with scaling, may be very accurately calculated for a multistation turbine on a minicomputer. In this paper, a five station rotor is evaluated to demonstrate the procedure. A method is presented in which the characteristic polynomial may be automatically generated by Leverrier’s algorithm. The characteristic polynomial may be directly solved or the coefficients of the polynomial may be examined by the Routh criteria to determine stability. The method is accurate and easy to implement on a 16 bit minicomputer.