Low Gravity Flight Complement Data

The structural and mechanical design and performance requirements for a space transportation system carrier which will accommodate essentially self-supporting low-g MEA and MAUS facilities are described. Also included are the mission requirements for the materials processing facility and MEA/MAUS experiment flight implementation reguirements

Stress-concentration factors for finite orthotropic laminates with a circular hole and uniaxial loading

Stresses were calculated for finite-width orthotropic laminates with a circular hole and remote uniaxial loading using a two-dimensional finite element analysis with both uniform stress and uniform displacement boundary conditions. Five different laminates were analyzed. Computed results are presented for selected combinations of hole diameter/sheet-width ratio d/w and length-to-width ratio L/w. For small L/w values, the stress-concentration factors K sub tn were significantly different for the uniform stress and uniform displacement boundary conditions. Typically, for the uniform stress condition, the K sub tn values were much larger than for the infinite strip reference condition; however, for the uniform displacement condition, they were only slightly smaller than for this reference. The results for long strips are also presented as width correction factors. For d/w less or = 0.33, these width correction factors are nearly equal for all five laminates

My Poetic Journey Maze

From a brief history of poetry, to words of scattered yet sympathetic thoughts my obsession with poetry will be unleashed. My thoughts and different approaches with this project will take on a few different short intoxicating narratives and excursions. Different sections of my project are simple yet complex indirect reflections of verbal asymmetrical shapes, and visual connections. Ultimately, you will be able to experience the visual connections through the photos that I took and my poetic approach. I hope this project is found to be seen as an exhilarating experience as I share my personal self, my thoughts on creativity, and the positive impact it can have on our youth. My world is filled with creative imagination, chaotic verbal chemistry, and divine surprises. Here is where you will take a journey with me through this wild maze that you may not directly understand, but indirectly I will make sure is understood. Creatively and ultimately the maze will also reflect the game connect the dots in a divergent and convergent formality. This complicated, yet tranquil maze will start out with caged in mental thoughts, my personal incubation moments, and questions to consider with the intent to make you think. The maze will also take on many twist and turns as the journey takes a walk with my daily mental and emotional self through words of expression. The art of poetry, what it sounds like, smells like, and feels like. The series of poems that I created seem to be appropriate to the narrative are presented for eyes to see and wisdom to gain. You never know you might just find some value in this journey maze and may even feel yourself being able to relate to the subject matter

Development Of Grading Rules For Re-Cycled Timber Used In Structural Applications

Until recently, the usual method of disposal of timber used in structures has been demolition and disposal. For example, at the time of writing, Australians are placing approximately 1 million tonnes of wood waste into landfill sites. However, reduced availability of native hardwoods has created a situation where use of recycled timber has significant environmental and economic potential, particularly where recycled products can be incorporated into new construction or in some cases retro-fitting of existing buildings and structures. Currently, there are no standards or recommendations for assigning design properties for structural reuse of wood and the use of recycled timber in decorative products tends to rely on subjective application of visual grading rules developed for new timber. In order to address this problem and utilise the recycled timber resource effectively and reliably, the authors have undertaken a research project (funded by the Forest and Wood Products Association). The aim of this project is to develop appropriate (visual) grading systems that take into account the properties of recycled timber; in particular, how the history and previous use of the timber has effected its properties in terms of being fit for purpose in a re-use application. The paper will present the findings of this project involving research to quantify the mechanical properties and develop appropriate (visual) grading systems that take into account the properties of recycled timber; for use in both structural and aesthetic applications

Screw- and nail-gluing techniques for wood composite structures

Composite systems enhance the structural capacity and reliability of wood solutions for structures. With today engineered wood products and structural adhesives, high performing structures can be constructed. Hybrid assembly techniques that combine mechanical fasteners and an adhesive (screw- and nailgluing techniques) allow manufacturing large dimension composite structures with reasonable infrastructure. They also give full composite properties to the interlayers. Furthermore, these hybrid connections can experience ductility. This paper presents a research on small-scale glued assemblies which were manufactured using screw- and nail-gluing techniques. It discusses qualitative and quantitative analyses that confirmed the full-composite properties and ductility of the interlayers. The analyses also show that superposing the behaviour of both connectors is reasonable to predict the strength and slip modulus of hybrid connections. © 2007 Taylor & Francis Group, London

Understanding the composite characteristics of stressed-skin panels

The composite properties of stressed-skin panel (SSP) systems are characterised by the interaction ? composite action ? and the portion of the sheathing acting with the joists ? the tributary width. A discussion on the tributary width forms the focus of this paper. An analysis, which has been conducted considering the pattern of the strain distribution in the sheathing(s), is presented. It uses laboratory data of a major research project conducted at the University of Technology, Sydney, between 2002 and 2007 (Gerber 2007). This analysis indicates that under strict conditions, in particular structurally glued interlayers, a large portion of the sheathing contributes to the structural behaviour of SSP structures. A better use of the mechanical properties of the panels is also achieved. This paper also presents an analysis on the effects of discontinuities in the sheathing. It has been identified that such event causes a significant reduction of the sheathing contribution

RISK AND SUSTAINABLE AGRICULTURE: A TARGET-MOTAD ANALYSIS OF THE 92-YEAR "OLD ROTATION"

Target-MOTAD was used to assess the risks and returns of sustainable cotton crop rotations from Auburn University's 92-year "Old Rotation." Study results analyze rotations of continuous cotton, with and without winter legumes; two years of cotton-winter legumes-corn, with and without nitrogen fertilization; and three years of cotton-winter legumes-corn and rye-soybeans double-cropped. Ten years of observations on deviations from target income were used to identify optimal sustainable rotation(s). Study results suggest that diversification in rotations, as well as in crops, results in the least risk for a given level of target income.Risk and Uncertainty,

Computer Simulations of Timber-stressed Skin Panels Using Finite Elements

A Finite Element Model (FEM) can provide a helpful and accurate tool for acquiring a better understanding of complex structures such stressed skin panel (SSP) systems and can contribute towards saving costly experiments. Because SSP constructions are highly complex, orthotropic, statically indeterminate and multi-layer assemblies and their members are orthotropic, and have viscoelastic properties and non-linear behaviour under certain conditions, accommodating SSP systems into a FEM is an arduous task and inevitably represents an idealisation of the physical structures

Accessible and reliable design of stressed-skin panels - An Australian perspective

Stressed-skin panel (SSP) technology possesses many advantages and the subject research program has increased the understanding of SSP structures with respect to serviceability and ultimate resistance performance. In order for the building industry to capitalise on the results of this research, it is essential that the codes i.e. AS 1720.1-1997 (Australian Standard™ 1997) should embrace a design procedure enabling the use of the full potential of SSP systems. This paper outlines an amendment proposal to Section 5 of AS 1720.1-1997 that will enable designers to achieve a problem-free and efficient implementation of SSP technology. It focuses on the aspects of the tributary width of the sheathing and the stress determinations in the composite section. The proposed design procedure is both useable and straightforward to implement and satisfies requirements of structural safety and comfortable serviceability. It is based on a solid research background and relates to EC5 (European Committee for Standardisation 1995), which will necessitate some adjustments to fully comply with Australian design standard. © 2007 Taylor & Francis Group, London

Stress-concentration factors for finite orthotropic laminates with a pin-loaded hole

Stresses were calculated for finite size orthotropic laminates loaded by a frictionless steel pin in a circular hole of the same diameter. The calculations were based on finite element analyses for six laminates. Stress concentration factors, based on nominal bearing stress, were determined for wide ranges of the ratios of width to diameter, w/d and edge distance to diameter, e/d. An infinite laminate case was analyzed for each laminate. Orthotropy had a significant influence on the tensile stress concentration at the hole. For example, the stress concentration factors for the infinite laminate cases ranged from 0.82 to 2.16, compared with 0.87 for the quasi-isotropic laminate. The finite widths and edge distances strongly influenced the tensile stress concentration. For the practical range w/d or = 3, the peak tensile stresses were as much as 80% larger than the infinite laminate reference value. For e/d or = 3, these stresses were amplified by as much as 50%. In contrast, the finite width and edge distance had little effect on shear-out and bearing stress concentrations