Bearing strength of wood under steel aircraft bolts and washers and other factors influencing fitting design

The purpose of this report is to correlate, bring up to date, and put under a single cover all the information thought to be essential to an understanding of the formulas

Mother-loss: A Phenomenological Exploration of the Experience of Losing a Mother

The death of a mother can be devastating to a child. The purpose of this study was to qualitatively explore the experience of early maternal loss for adult women who were younger than 4 years old when their mothers died. This study focused on the phenomenon as it was perceived by these women and how the loss has impacted their lives across time. The theoretical frameworks used to guide this study were attachment theory, symbolic interaction theory and family stress midrange theory, and risk and resilience midrange theory. An adult women who has grown up without a mother indeed may have attachment insecurity. There is empirical evidence to support the assertion that attachment insecurity can lead to adult outcomes such as depression, alcoholism, and other psychopathological responses. For this study, a sample of 8 women was interviewed for approximately 2 hours each using intensive, interactive interviewing. Their words provided the data that informed this study. The themes that emerged as the most significant from these interviews were the presence of another female attachment substitute, fathering, religious beliefs, and memories of mothers. Most significant was the presence or absence of another woman who could step into the role left vacant by the death. If this woman provided loving and nurturing care for the young girl, grieving and suffering were short-lived. However, if she did not provide love and warmth, if she was abusive, or if there was no alternate attachment figure available, there were possibly ongoing deleterious results

The Design of Plywood Webs for Airplane Wing Beams

This report deals with the design of plywood webs for wooden box beams to obtain maximum strength per unit weight. A method of arriving at the most efficient and economical web thickness, and hence the most suitable unit shear stress, is presented and working stresses in shear for various types of webs and species of plywood are given. The questions of diaphragm spacing and required glue area between the webs and flange are also discussed

The Influence of the Form of a Wooden Beam on Its Stiffness and Strength I : Deflection of Beams with Special Reference to Shear Deformations

The purpose of this investigation was to determine to what extent ordinary deflection formulas, which neglect shear deformations, are in error when applied to beams of various sections, and to develop reasonably accurate yet comparatively simple formulas which take into account such deformations. A great many tests were made to determine the amount of shear deformation for beams of various sections tested over many different spans. As the span over which the beam is tested is increased the error introduced by neglecting shear deformations becomes less, and the values obtained by substituting measured deflections in the ordinary formulas approach more nearly the modulus of elasticity in tension and compression. For short spans the error is considerable and increases rapidly as the span is reduced. Two formulas were developed for estimating the magnitude of shear deformations, both of which have been verified by tests. The first assumes the parabolic distribution of shear on a cross section of a beam and, starting with a differential volume, the distortion due to shear is determined by the ordinary methods of summarizing the work. The second assumes that the deflections due to shear in any two beams of the same length, height, and moment of inertia, which are similarly loaded, are proportional to the summations of the shear stresses on their respective vertical sections. Both formulas check experimental results very closely when the calculations are made with great refinement

The Influence of the Form of a Wooden Beam on Its Stiffness and Strength II : Form Factors of Beams Subjected to Transverse Loading Only

The general aim of the investigation described in this report is the achievement of efficient design in wing beams. The purpose of the tests was to determine factors to apply to the usual beam formula in order that the properties of wood based on tests of rectangular sections might be used as a basis of design for beams of any sections and if practical to develop formulas for determining such factors and to verify them by experiment. Such factors for various sections have been determined from test by comparing properties of the beam in question to similar properties of matched beams 2 by 2 inches in section. Furthermore, formulas were worked out, more or less empirical in character, which check all of these test values remarkably well