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.
Background
A composite material is a combinant of more than one material where each material retains its own material properties. Composite materials are used throughout modern society and in nature because they provide material properties that individual materials could not provide on their own.
In the specimens, all showed a brittle fracture due to how the stress vs strain slope looked and where the Ultimate Tensile Strength was located. Also, how the composited specimens failed look consistent that there were any defects in the specimens. The 0°/90° carbon/epoxy specimen failed in the longitudinal direction because of how the fibers were aligned in that direction. The two ±45° glass/ epoxy specimen failed in the 45-degree direction do to how the fibers were aligned in the specimens. These failures would make sense because composites fail when fiber become unconnected so the epoxy failed first and then cause the fibers to fail next. The fibers individual are weak but when are combined and form a pattern with other fibers is how the strength
Use a Mathcad script to determine the procedure used during the manufacture of a wound laminate composite tube and to assess its validity for use in stress and strain analyses.
However, the absence of plastic deformation does not mean that composites are brittle materials like monolithic ceramics. The heterogeneous nature of composites result in complex failure mechanisms which impart toughness. Fiber-reinforced materials have been found to produce durable, reliable structural components in countless applications. The unique characteristic of composite materials, especially anisotropy, require the use of special design
Linear viscoelastic behaviour of the polymer composite with in the glass transition temperature can be addressed using cole-cole plot. Cole-cole plot is obtained by plotting loss modulus(E”) against
Composite materials have been evaluated with a matrix properties unsaturated polyester resin by conducting mechanical testing, including the pressure, compression, hardness and impact resistance.. While wood flour helped add to the balance between the original compression strength reductions up to 3 wt. wood flour and then reduce the strength. The results confirmed that the best promote and 3% by weight of wood flour consider the compression strength
In the 1930s, numerous synthetic composite technological breakthroughs were born. “In 1935, Owens Corning launched the fiber reinforce polymer (FRP) industry by introducing the first fiber glass. In 1936, unsaturated polyester resins were patented. Because of their curing properties, they would become the dominant choice for resins in manufacturing today. In 1938, other higher performance resin systems like epoxies also became available.” (Cite) The creation of FRP was vital to the military during World War II due to its notably high to strength to weight ratio. Not only was FRP used for electronic housings and other electronic components, but was also used to create the first fiberglass reinforced boat hull. The war efforts spawned copious amounts of commercial products made with FRP. This is how synthetic and natural composites were revolutionized during the 20th century.
This paper discusses the different properties of composite materials under static testing condition to determine the effect of aging due to change in temperature and moisture content. Effects on tensile, shear, impact, stiffness and fatigue parameters are studied. For each property, application specific composite materials are taken into consideration with different stacking sequence and number of plies. Different samples of these are then introduced to different hygrothermal environments for example: temperatures ranging from -50 degree Celsius to +50 degree Celsius or kept in wet conditions for 24 hours at different temperatures of 21, 37 and 50 degree Celsius etc. Different tests are performed based on the material property to observe a change from the initial unaged specimen. To study every property a different test method is discussed. A final comparison for each property between the unaged and aged specimen is shown in order to see the property’s dependence on temperature and moisture. This comparison highlights the temperature and moisture dependent properties and showcase a trend. Properties like tensile modulus, shear modulus, shear strength, flexural stiffness and fatigue life show a decrease with increase in temperature and moisture content while Poisson’s ratio and impact strength increase with increase in temperature and moisture content.
Introduction: The available life cycle cost (LCC) models and procurement strategies do not take into consideration the varied manufacturing techniques for advanced composite materials. The increased use of advanced composite materials in aerospace
Polymer Matrix Composites: Most commonly used matrix materials are polymeric. In general the mechanical properties of polymers are inadequate for many structural purposes. In particular their strength and stiffness are low compared to metals and ceramics. These difficulties are overcome by reinforcing other materials with polymers. Secondly the processing of polymer matrix composites need not involve high pressure and doesn’t require high temperature. Also equipments required for manufacturing polymer matrix composites are simpler. For this reason polymer matrix composites developed rapidly and soon became popular for structural
Carbon Fibre – Carbon fiber composite is an increasingly popular non-metallic material commonly used for bicycle
Composite materials are the engineering materials made from two or more constituent materials they remain separate and distinct on a macroscopic level but forming a single component or Composites can defined as materials that consist of two more chemically and physically different phases separated by a distinct interface(matrix phase and dispersed phase). The different systems are combined judiciously to achieve a component with more and more useful structural or functional properties non-attainable by any of the constituent alone. In the composites usually Matrix phase is the primary or base phase having a continuous character or continuous molecular chain. But these Matrixes are usually less hard and more ductile phase. In composites it holds the dispersed (reinforcing) phase, shares a load with it. The Dispersed phase is encapsulated in the matrix in a discontinuous form called a secondary phase. This Secondary phase is usually stronger than that of the matrix phase, so is also called as reinforcing phase.
Composite materials are multiphase materials obtained through the artificial combination of different materials in order to attain properties that the individual components by themselves cannot attain. They are not multiphase materials in which the different phases are formed naturally by reactions, phase transformations, or other phenomena. An example is carbon fiber reinforced polymer. Composite materials should be distinguished from alloys, which can comprise two more components but are formed naturally through processes such as casting. Composite materials can be tailored for various properties by appropriately choosing their components, their proportions, their distributions, their morphologies, their degrees of crystallinity, their crystallographic textures, as well as the structure and composition of the interface between components. Due to this strong tailor ability, composite materials can be designed to satisfy the needs of
This deals with bending Finite Element Analysis of the aircraft wing using commercial software ANSYS. An aircraft wing is made of composite with fibre angles in each ply aligned in different direction. Various air foil thickness and ply angles were considered to study the effect of bending-torsion decoupling. The laminate characteristics are usually calculated using the number of layer, stacking sequence, geometric and mechanical properties. A finite number of layers can be combined to form so many laminates. The only restriction that is imposed on the laminate as an element of composite structure concerns its total thickness which is assumed to be much smaller than the other dimensions of the structure.
The objective of this lab is to find the relationship between tensile stress and strain for various materials. The Stress-Strain Apparatus stretches (and in some cases breaks) a test coupon while it measures the amount of stretch and force experienced by the test coupon. Software is used to generate a plot of stress versus strain, which allows Young's Modulus, the elastic region, the plastic region, the yield point,
The tests were conducted with five spindle speeds (690,960, 1153, 1950, and 2500) rpm’s, feed rates (0.6, 0.8, 1.0, 1.2, and 1.4) mm/s and depth of cuts (0.5, 1.0, 1.5, 2.0 and 2.5) mm as shown in ‘’Table 1’’. E-Glass uni-directional GFRP [±450]12 composite materials (general polyester matrix) was employed for the tests. The material was fabricated by hand lay-up compression moulding technique. In the manufacture, 12 layers of E-Glass fiber mats (300mmx300mm) were laid up on flat 10mm thick mould panel. A mixture of polyester resin and hardener at 10:1 ratio was stirred in a glass mug. And the ready mixture is poured into the E-Glass preform and compressed under a pressure about 200Kgf and temperature of 500C. The resin has cured after 4 to 5 hours; the laminates were cut into 100mmx100mmx10mm size using a