Detailed analysis and test correlation of a stiffened composite wing panel

Nonlinear finite element analysis techniques are evaluated by applying them to a realistic aircraft structural component. A wing panel from the V-22 tiltrotor aircraft is chosen because it is a typical modern aircraft structural component for which there is experimental data for comparison of results. From blueprints and drawings supplied by the Bell Helicopter Textron Corporation, a very detailed finite element model containing 2284 9-node Assumed Natural-Coordinate Strain (ANS) elements was generated. A novel solution strategy which accounts for geometric nonlinearity through the use of corotating element reference frames and nonlinear strain displacements relations is used to analyze this detailed model. Results from linear analyses using the same finite element model are presented in order to illustrate the advantages and costs of the nonlinear analysis as compared with the more traditional linear analysis. Strain predictions from both the linear and nonlinear stress analyses are shown to compare well with experimental data up through the Design Ultimate Load (DUL) of the panel. However, due to the extreme nonlinear response of the panel, the linear analysis was not accurate at loads above the DUL. The nonlinear analysis more accurately predicted the strain at high values of applied load, and even predicted complicated nonlinear response characteristics, such as load reversals, at the observed failure load of the test panel. In order to understand the failure mechanism of the panel, buckling and first ply failure analyses were performed. The buckling load was 17 percent above the observed failure load while first ply failure analyses indicated significant material damage at and below the observed failure load

Effect of dietary fat on cholesterol absorption, synthesis and transport in the preruminant calf

Seventeen preruminant male calves were prepared surgically with lymphatico-venous shunts and/or re-entrant gallbladder to proximal duodenum shunts to evaluate the effects of the degree of saturation of dietary fat upon cholesterol transport in the intestinal lymph and bile and cholesterol transposition from blood capillaries to the intestinal lymph. Liquid diets were formulated to contain 12.5% dried skim milk (SM) or 10.5% SM to which was added 2% soybean oil (SBO), milk fat (MF), beef tallow (T) or a fat plus supplemental cholesterol. Calves received each diet for 3 days at 8% of body weight per day in two equal feedings. Following completion of each three day dietary treatment, total lymph collections were made for 15 min of each hour, 1 h prefeeding and 12 h postfeeding, to determine flow rate, total lipid and cholesterol transport. Total bile collections were made during the same time span to determine flow rate, cholesterol and bile acid transport. Transposition of cholesterol from blood capillaries to intestinal lymph was determined by injection of 100 (mu) Ci 4-(\u2714)C-cholesterol into the blood of calves at feeding time. To avoid recirculation of 4-(\u2714)C-cholesterol via the enterohepatic circulation, bile was diverted and replaced with bile from a donor calf fed an identical diet. For the SM, SBO, T and MF diets, respectively, cholesterol transported in the mesenteric lymph averaged 1.09, 1.92, 2.70, and 2.41 mg/(h x kg body weight); average lipid transport in the mesenteric lymph was 8.94, 32.58, 38.12 and 64.86 mg/(h x kg body weight); cholesterol transposed from capillaries was 44, 61, 48 and 36% of the cholesterol transported in the mesenteric lymph. Source of fat or addition of supplemental cholesterol had no effect on amount of cholesterol or bile acid transported in the bile; however, calves fed SM transported greater quantities of cholesterol in the bile than did calves fed fat or fat plus cholesterol. Our method allows for simultaneous determination of cholesterol absorption and excretion, as well as calculation of intestinal cholesterol synthesis

CAMPUS STORYTELLING NETWORKS AND STUDENT RETENTION INTENT

In an effort to better understand retention, a survey was developed to ask students at a southern land-grant university how they communicate with each other. Communication Infrastructure Theory (CIT) was previously used to identify communication networks in urban neighborhoods. My thesis adapted this theory and networks to identify the strength of three communication techniques of college students and how it effects a student’s sense of belonging which can impact that student’s intent to stay in school

Global atmospheric measurements experiment on tropospheric aerosols and gases (GAMETAG)

Issued as Final report, Project no. G-35-650 (continuation of Project no. G-35-632

Atmospheric nitrogen oxides : their detection and chemistry

Issued as Progress report, Quarterly reports [nos. 1-6], and Reports, nos. 1-3, (includes subprojects nos. E-16-699/Bailey/AE & A-3743/Sinclair/EML

A vacuum-ultraviolet photofragmentation

Issued as Progress report, and Final report, Project no. G-35-68