PREDICTING THE STRENGTH OF WOOD-JOIST FLOORS.
Abstract : This study was intended to explore the relationships between strengths at first rupture predicted by linear and nonlinear models for wood-joist floors of a given configuration but having various combinations of joist material properties. The study produced two ways of altering linear models to account for the nonlinear behavior of nails in floors loaded to failure. The strength at first joist failure of 72 floors was analyzed using linear and nonlinear finite-element models and statistical comparisons. The results of the study are presented in two forms. The first is recommended factors by which the predicted failure loads from the linear analysis can be scaled to give failure loads consistent with the nonlinear analysis. The second is recommended substitute nail stiffness which can be used in a linear analysis to predict floor responses with near-equivalent accuracy as provided by a nonlinear analysis. The results presented are specific to the floor design used in this study, but similar techniques could be used to derive equivalent information for other floor designs.
FEAFLO: A program for the analysis of layered wood systems
Abstract A finite element method for the analysis of planar layered wood systems is described. The method includes the effects of slip between layers due to fastener deformations, orthotropic material properties and gaps in layers. The method was used in developing program FEAFLO (Finite Element Analysis of FLOors). Data computed at each node include the deflection, rotations, fastener forces and for each layer the axial displacements, axial forces, moments, shears and extreme fiber stresses. The method was verified by comparing measured and predicted behavior for T-beams and wood joist floors. A listing of program FEAFLO, written in ANSI FORTRAN IV, is given. The input and output data for an example floor are also given.
Aristocratic Century: The sinews of power: political
In his excellent book on the Secretaries of State, Mark Thomson offered ‘the paradox of continuing domination of the aristocracy and the simultaneous insignificance of the House of Lords, per se ’. It is true that, by the beginning of the eighteenth century, the supremacy of the House of Commons in financial matters was a wellestablished convention. The claims of the Commons to an undisputed control over money matters, which had been urged before the Civil War, were resumed immediately after the Restoration and a protracted dispute with the House of Lords began. In 1661 the Lords resolved that there were no precedents in history for this new claim by the House of Commons. In 1671, the Commons retorted that taxation ought not to be questioned by the Lords and in 1678 they reiterated that supply was ‘the undoubted and sole right of the Commons’ and ‘ought not to be changed or altered by the House of Lords’. The Lords' attempt in 1692 to assess their own taxes was also abandoned, though they retired under cover of a rather insubstantial smoke-screen that they maintained their power of amendment to be a ‘fundamental, inherent and undoubted right from which their lordships can never depart’. That established, they departed. Geoffrey Holmes quotes a nice example from 1702 when the bishop of Carlisle found himself the only peer answering to a money bill, ‘no other lord in the House regarded what was doing, this being only (pro forma) to preserve a seeming right to dissent from, or amend, any part of a money bill’.