Information reviewed and reaffirmed, 1962. Original report dated June 1943. This report is one of a series issued in cooperation with the Army-Navy-Civil Committee on Aircraft Design Criteria under the supervision of the Aeronautical Board.
This report is one of a series issued in cooperation with the Army-Navy-Civil Committee on Aircraft Design Criteria under the supervision of the Aeronautical Board.
This thesis investigates a simple dynamic model of the hind leg
of a beetle during initiation of a step. The primary assumption was
that the full load of the body was carried on the hind leg during
this time. That is, the only forces on the body were that of...
This paper describes the results of a project conducted to determine
the magnitude of and the parameters affecting the magnitude of the
cable tensions generated during lateral yarding operations in a cable
thinning. Specific emphasis was placed on measuring mainline tensions
as a function of turn weight, turn length, mainline...
This thesis explores the use of human kinesthetic input to advance robotic grasp planning. It specifically focuses on identification of human heuristics of grasp similarity by extensive human-subject experiments. This heuristic is then utilized to develop a robust metric for identifying similar robotic grasps. The central hypothesis of this work...
Bulk metallic glasses (BMGs) offer a great deal of potential through their near-theoretical strength, potentially high toughness and unique forming and molding traits. However, there are still a number of outstanding issues that bar their widespread use. This thesis describes the investigation of three research questions each designed to further...
Identifying material characteristics of composites is important in designing any
structural system. The aerospace industry relies on these material properties not only to
design a functional aircraft, but also a safe and reliable one. Since carbon fiber
composites are relatively new materials, little is known about its characteristics under
certain...
Epoxy resin is a thermosetting resin that is commonly used as composite matrix. Epoxy composite materials are well utilized in industries, such as aerospace, due to their good mechanical properties. Nano-scale filler reinforced polymer composite materials have been intensively researched in recent decades. Cellulose nanocrystals (CNXLs) are a type of...
Angular correlations of gamma rays from excited states of ¹⁶⁶Er have been
measured following the β decays of ¹⁶⁶ Ho (Jπ =7-, t 1/2 =1200y, Q= 1854 ke V) and ¹⁶⁶Tm (Jπ = 2+, t 1/2, = 7.7h, Q=3040 keV).
Data was collected using the 8π
spectrometer, an array of...
Identifying material parameters in composite plates is a necessary first step in a variety of structural applications. For example, understanding the material parameters of carbon fiber composite is important in investigating sensor and actuator placement on micro-air-vehicle wings for control and wing morphing purposes. Knowing the material parameters can also...
The development and some applications of holographic optical tweezers (HOT) are presented. Our HOT system uses a spatial light modulator (SLM) to control the location and properties of the optical trap. We have developed a method for optimizing the diffraction efficiency of a SLM that can be applied in situ...
This report is one of a series issued in cooperation with the ANC-23 Panel on Sandwich Construction of the Departments of the Air Force, Navy, and Commerce. Information reviewed and reaffirmed 1960. Original report dated August 1955.
The goal of this project is to contribute to the development of design values for cross-laminated timber (CLT) diaphragms in the seismic load-resisting system for buildings. Monotonic and cyclic tests to determine strength and stiffness characteristics of 2.44 m (8 ft) long shear connections with common self-tapping screws were performed....
This study consists of three parts: 1) Part A: Limiting Height Evaluation for
Composite Wall Tests, 2) Part B: Mid-Span Deflection Evaluation for Composite Wall
Tests, and 3) Part C: Nominal Axial Strength Evaluation for Wall-Braced Wall Stud
Columns.
The purpose of Part A is to develop experimentally-based limiting heights...
Dental resin composites are widely used in modern dentistry due to their aesthetic appearance. However, resin based restorations have inferior mechanical properties (fracture is the second reason for restorations replacement) in comparison to alloy based composites and their antimicrobial properties still remain poor, leading to secondary tooth decay development on...
A novel method for isolating fish proteins by shifting pH to high acid or high alkali pH was the focus of the study. Biochemical and physicochemical properties of various pH-treated soluble fish proteins as a function of ionic strength were determined. Effect of ionic strength and various storage conditions on...
The dependent transfer of a traveler with disabilities on board an aircraft places the transferors, as well as the traveler, at risk of disabling lower back injury. This risk is increased on board an aircraft due to the confined space in which the transfer takes place. The purpose of the...
The breaking radii of variously discolored veneers of six different hardwood species were small enough, for most of the discolorations, to indicate that such veneers can be used successfully on members having curved surfaces. When expressed in terms of the minimum radius of curvature attained without fracturing, the breaking radius...
Hydrogel polymers are a novel class of hydrophilic materials that have large application areas in both the industrial and medical fields. Carboxymethyl cellulose (CMC) has received attention as a hydrogel polymer. Methods to modify the mechanical properties of gels and films made from CMC are of interest in our lab...
High density polyethylene (HDPE) is a ubiquitous material with versatile properties. It is produced and used in greater volume than any other thermoplastic. HDPE is often filled with a variety of materials for various applications. Glass fiber and wood flour are two common fillers for HDPE. Recently there has been...
This report is one of a series issued in cooperation with the Army Air Forces and the Bureau of Aeronautics under the supervision of the Aeronautical Board.
The structural and stress changes in molybdenum/amorphous silicon (Mo/a-Si)
EUV reflecting multilayers during annealing at 316°C were studied. The amorphous
interlayers, with an Mo:Si stoichiometry of 1:2, grew during annealing. The residual
stresses in each component of the multilayer also changed significantly. Through high
resolution electron microscopy, selected area electron...
The mechanical performance of composite materials is determined by the mechanical properties of their individual components and the effective load transfer between these components. Binders are commonly used to bond composite components together and to provide effective load transfer between them. In wood-based composites the binder-component load transfer occurs at...
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Lech Muszyński
The mechanical performance of composite materials is determined by the
Effects of moisture content, pH, and salt concentration on dynamic rheological properties and gel fracture quality of Pacific whiting surimi were investigated. Torsion tests showed that shear stress decreased rapidly and strain values decreased gradually as moisture concentration increased. As pH increased, fracture shear stress and strain values increased, whereas...
The tendency of wood to shrink and swell with changing moisture content remains as one of the most significant challenges to using wood in its many applications. Viscoelastic Thermal Compression (VTC) has been shown to significantly increase the density, strength and stiffness of wood. However, dimensional stability is still a...
During heel-toe running, the vertical ground reaction force (VGRF) profile has both impact and active peaks. Although the mass-spring model (a single mass and a linear spring) is simple and useful to predict running characteristics, its simulation of VGRF profiles produces only a single peak rather than the double peak...
Information reviewed and reaffirmed, 1962. Original report published in 1946. This report is one of a series issued in Cooperation with the Army-Navy-Civil Committee on Aircraft Design Criteria under the supervision of the Aeronautical Board.
This report is one of a series issued in cooperation with the ANC-23 Panel on Composite Construction for Flight Vehicles of the Departments of the Air Force, Navy, and Commerce.
Steady flow fields and flow-induced wall stresses have been evaluated by experimental measurements and computational fluid dynamics (CFD) analysis in a series of patient-specific abdominal aortic aneurysm (AAA) models, over a range of Reynolds numbers (Re) from 125 to 3000 (500 to 3000 for CFD). Experimental methods used particle image...