Equivalent Model Essay

This report details the process for the design of a composite laminate tube, the software package 'MathCAD' was used to determine a lamina design with a configuration that avoids mechanical failure under loading conditions. It was also used to obtain twist angles and maximum stresses for specific lamina wind up angles. The report will provide analysis of the methods used to obtain these criteria.

In Figure 4, Young's modulus is plotted against yield strength. The diagonal line in the figure represents the material index M= σy/E. Materials below the diagonal line are the best candidate materials because they will remain elastic while providing the maximum conformability. All materials that cost more than $2.20 per pound and have a UV rating of "poor" were eliminated. Also, only materials that can be made through the polymer extrusion process were considered. The candidate materials are listed in Table 1 and ranked by the material index. The current material, TPV, is included in the table for

* The LOP model was based on a study by Craik & Tulving (1875) who

Experiment Two: Stiffness Report from laboratory work performed on 12 May 2011 as a part of the unit of study CIVL2201 Structural Mechanics

The web of the prefabricated truss can be analyzed as a column. Burdzik analyzed the web of a truss as a non-continuous compression member. Columns must take the effective length into account for both the in plane and out of plane bending. The connection type, continuity, and capacity of adjacent members affect the degree of restraint for the web member (Burdzik,

The team decided to do numerous stress analyses and at least five experiments. The experiments served as a great learning experience because they taught the group the possibilities of what to use in the roadway and basic lessons on how to handle tension and compression. For example, Terence created a “sandwich” under-support to view how it would fair as a system of under-support in the final build. This sandwich involved gluing five members together and then diagonally layering it with seven sticks. Lastly, he glued five more sticks on top of the diagonally layered members. This was an excellent experiment because this “sandwich” would not break, even after Terence put his full weight and his sister’s old college books on it; however, it weighed thirty grams, making it essential to use only on the most crucial parts of the bridge.Next, there was the water experiment, during which Terence submerged three Popsicle sticks in water for four days. This experiment proved that the sticks would not bend as much as one would expect them to; in fact, they would only bend in a clockwise or counter-clockwise position. Finally, there was the experiments of the trusses. In these experiments, Terence created a double-layered Triangle Truss that held three hundred pounds and an X Truss that could hold only thirty pounds. In the end, this experiment taught the group that a simple X Truss would not satisfy the final build and that triangles were

However, composites are not wonder materials, in the aviation world, and do have their own disadvantages. Internal damage to composite materials, from a low speed impact, though it shows no external or surface evidence, could result in delamination between the internal layers, or plies of composite material. It is in these circumstances that structural engineers have concerns regarding complex repairs structural tolerances. Because of the threat of delamination, engineers who design composite structures take special care to make certain that loads placed on the composites are primarily in plane -- where the fibers are strong -- and that buckling does not occur. Compounding the difficulties confronting engineers, composites cannot be inspected for weakness or internal damage in the same way that metals can. Delamination and cracks in the composite matrix are usually internal to the composite and will not be visible from the surface. Techniques are available to find such faults -- such as the embedded sensors previously mentioned -- but they require a different methodology than that to which the

The purpose of this lab is was to expose students to the manufacturing, fabrication, and testing of composites. In addition, it provides students with experience analyzing tensile and bending failures of composites. Three tensile specimens and two bend test specimens were tested during this lab. The tensile specimens were a wet lay-up of bi-directional E-glass, and the bend specimens were made up of a nomex honeycomb core with pre-preg uni-carbon faces. The three tensile specimens were tested, their elastic modulus and ultimate tensile strength calculated, and these value were compared to published approximately equivalent material properties. The two bend test specimens were tested, their face bending stresses were calculated, the shear stress in the core was calculated, and the bending and shear stresses were compared to published approximately equivalent material properties. A failure mode analysis was conducted for both the tensile and bend test specimens. This report summarizes the theory, procedure, and machines associated with the lab. Furthermore, it graphically and verbally displays the results draw from lab, and provides conclusions to improve the lab in the future.

Composite materials are becoming more and more attractive to aircraft designers, due to the rising cost of fuel. Composite materials are material made from two or more constituent materials with significantly different physical or chemical properties that, when combined, produce a material with characteristics different from the individual components. The different characteristics of composites can determine where and how they are used, to how they are designed and analyzed (Campbell, 2010). Composites can be used to replace structures that were originally made of strong light metals in aircraft structures. These materials can be just as strong as metal, without the added weight. Studies have shown that one of the benefits of using composite materials in aircraft designs, is that the total weight of the aircraft is reduced (Henry,

Residual stresses [1, 2] are of great importance in any manufacturing industry as it plays a major role in determining the structural integrity of the component being engineered. Residual stresses highly influence the strength, stability, resistance, fatigue life and performance of the component manufactured. These properties being affected leads to failure and repair of the component or the entire structure. Hence it is essential to measure the residual stresses present in a component and to relax these stresses to improve the performance and reliability of the component. A residual stress analysis in design phase is compulsory in order to estimate the reliability of the component [1].

Thin walled structures are an important part of engineering construction with territories of use becoming diverse continuously ranging from girder bridges, oil vessels to industrial warehouses , framed structures. Thin walled sections have various stresses and failure modes which can be difficult to predict. Thus structural engineers need help of computers for analysis of these structures. This has been done by using software called THIN-WALL which estimates the cross-sectional properties of the section according to the Vlasov theory. The method of input data for thin walled structure has been explained in this paper. Also the buckling analysis of the thin walled sections has been done using CUFSM which is based on the finite strip method. This method has been explained in the paper and the results the analysis have been compared with the hand calculations according to the Canadian code s-16. The results have been discussed and on basis of this review conclusions have been presented.

In this paper the non-conventional reinforcement details of beam-column joint has been discussed. The non-conventional details includes using inclined crossed bars in the joint, and it can be placed as additional bars or by bending the longitudinal column’s bars. This paper first discusses types of joints, collapse of structures due to beam-column joint failure, explores some experimental studies about this type of reinforcement detail, and then the main advantages of using diagonal bars in the beam-column joint. Using diagonal bars has significant advantages for the beam-column joint: increasing ductility, affecting the

Honeycomb out-of-plane compressive properties are of interest for many researchers because they are important for the mechanical performance of sandwich panels, such as local compression and impact resistance. Bouakba et al (2012). Proposed a novel type Voronoi-lattice and study this honeycomb by FEA on in-plane mechanical properties using the ANSYS code. Many researchers have used FEA (e.g. numerical approaches) to better

Sandwich panels has been widely used in different kinds of constructions nowadays, though sandwich technology was confined almost entirely in aerospace applications before 1960s. From that time, their characteristics such as high strength to weight ratio and energy efficient started to attract engineers’ attention, and many research and studies enables them to be used safely in modern constructions. While sandwich panels can be made by the combination of a variety of materials, the structure of them always shares a same pattern. Two relatively thin and strong facings on both side, and a relatively light and thick core materials in the middle. It is also worth to notice that the shape of facings can be flat or profiled to satisfy different situations.

Composites are able to meet up diverse design requirements with considerable weight savings as well as elevated strength-to-weight ratio as compared to conventional materials. There are various types of composites such as Metal Matrix Composites (MMC), Particulate Composite (PC) and Fiber Reinforced Polymer composites (FRP). Among these composites, Carbon Fiber Reinforced Composites are widely