Numerical and Experimental Investigation of an Elliptical Paraboloid Shell Model
For practical engineering purpose, a new flat shell element baptized (ACM_Q4SBE1) is presented in this paper. The formulated element can be used for the analysis of thin shell structures; no matter how the geometrical shape might be. Tests on standard problems have been examined. Since, the analysis of thin shell structures has generally been purely carried out on a theoretical basis; it is of importance to present some experimental results of an elliptical paraboloid under uniformly distributed load pressure. The results obtained from both numerical and experimental work are presented. Index Terms— Elliptical Paraboloid, finite element, flat shell element.
Matrix Displacement Analysis of Anisotropic Shells by Triangular Elements
Over the last five years or so both in the USA (especially by the active group at Berkeley under R. W. Clough(7) ) and the UK, there have been a number of attempts to incorporate the plane triangular element under bending and membrane action into a general matrix displacement analysis of shells. All investigators stressed the positive aspects of the triangular element, which arise from its adaptability to any geometrical form of the shell, but noted at the same time some serious shortcomings due to a partial satisfaction of the kinematic compatibility conditions at the boundary. Thus we have within the Matrix Displacement Method the rather unusual example of a type of element whose deficiency with respect to kinematic compatibility does not automatically ensure convergence to the exact result as the number of elements is increased.
Measurement and Demonstration of Thermal Expansion Coefficient
There are many classroom demonstrations, such as the ball-and-ring experiment, for showing the existence of thermal expansion of solids. The coefficient of linear expansion α (= increase in length divided by the original length times the change in temperature) may be measured in high school laboratories using a number of methods.1–4 In this paper we describe an especially simple experiment for determining α for a metal rod. It is based on the well-known optical lever method and is suitable for either a laboratory experiment or a classroom exercise.