The effects on the stress intensity factor of bonding repair patches over a crack in a large sheet under uniaxial loading are studied using two simple numerical models. The variation of the stress intensity factor with increasing crack length is investigated and results for repairs involving large elliptical patches are found to agree with a closed-form approximation. Further cases are considered where the patch is either rectangular in shape or less than a certain critical size. For such repairs the closed-form approximation for the stress intensity factor is shown to be unsuitable.

An economic numerical method has been developed to calculate the incompressible potential flow about complete aircraft configurations by taking advantage of the computational efficiency of the internal distribution of singularities. For wing and wing-like components, source and vorticity singularities are distributed on the respective mean camber surfaces, while the fuselage carries a source distribution on its wetted surface. The singularity strengths are obtained by satisfying the flow tangency condition at selected points on all the wetted surfaces of the configuration. No attempt has been made to consider wing or body vortex shedding or separation. The results of the present method were compared with other theoretical and experimental data.

Two versions of the Sequential Quadratic Programming technique for constrained optimisation are described and used to solve some minimum weight design calculations for aircraft wings. The problems and the solution methods are described and discussed in some detail: but the main feature of the work is the use of the programming language Ada for writing the necessary software. Some features of the language are illustrated which appear to be valuable for many kinds of numerical computation. In particular, it is also shown that Ada facilitates the calculation of the partial derivatives of function and constraint expressions which are required in optimisation calculations but which are often quite difficult to obtain in practice.

A finite element method is used for the solution of the full-potential equation in conservation of mass form. The finite element analysis allows the boundary conditions to be treated in simple and exact manner, without the use of a mapping scheme. An efficient finite element computational grid is employed in order to obtain an accurate converged solution. An iterative method is used to solve the full-potential equation. The iteration is in two parts, new values for the velocity potential are found by matrix inversion while the density is not updated, then new values of the density are found from the isentropic relation. The density field is then relaxed using new values for the potential in conjunction with an artificial viscosity. Results are obtained for different types of axisymmetric configurations. Comparison is made with available experimental data and good agreement is found for the pressure coefficient distribution over a suitable blunted cone-cylinder axisymmetric body. Further comparisons with experimental data are required in order to assess the method.

The transfer matrix method of structural analysis is applied to the problem of beams subjected to large deflections by dividing the beam into a large number of uniform sections and applying elementary bending theory to each section. The solution using this method is compared with the theoretical solution of Bisshopp and Drucker for large deflections in uniform cantilever beams. The method has also been applied to uniform and tapered cantilever beams at various angles to the horizontal under vertical point loading and the results compared with experimental data obtained from laboratory measurements.