1. Introduction
The Charpy Impact Test, invented in 1900 by Georges Augustin Albert Charpy, is a comparative test that measures the energy absorbed by a test specimen under an impact load. The test specimen is usually notched across one of the larger dimensions on the opposite side of the impact area. [1]
The Charpy Impact Test is commonly used to determine the relative or impact toughness of a material and this test is used in quality control applications due to the fact that the test is fast and relatively cheap to conduct. Mainly the Charpy Impact Test is used to test metals, but it can also be used on polymers, ceramics and composites. [2]
After applying the Charpy Impact Test, materials can either be classified as brittle or ductile, with brittle materials absorbing small amounts of
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This usually happens when a material has undergone a process in which the material becomes more brittle and is less able to plastically deform. These processes include cold working or precipitation hardening.
2.4.2 Notches
The notch depth and tip radius is very important as some materials are more sensitive toward notches. Notches in the materials serve as stress concentration zones.
2.4.3 Temperature and strain rate
During impact most of the impact energy in the test specimen is absorbed as plastic deformation when the test specimen yields. Temperature and strain rate effect the yield behaviour and ductility of the material and hence affect the impact energy. Materials that behave this way usually have body-centred cube crystal structures and where lowering the temperature reduces the materials ductility.
2.4.4 Fracture
The purpose of this project was to understand the forces, momentum, and energy a contraption would experience during an impact from a pendulum at 5, 10, 15, 20, and 25mph. The project was required to hold and protect 2 raw large Grade A eggs from each pendulum impact respectively.
The Papanicolaou test in medical terms can also be known as or be called as the Pap smear, pap test, or smear test. It is a microscopic examination of cell .The purpose of this test is to perceive occurring of precancerous or existing cancerous cells in the opening uterus of the cervix. It also discerns asymmetry in the cells of the cervix (the bottom, narrow end of the uterus.)[1]
Fatigue failure can be divided in three parts i.e. Crack initiation, Crack propagation and Final rupture.
Four brass wedges were tested. Two were cold rolled to a thickness of 5.0 mm and two were cold rolled to a thickness of 2.5 mm. One wedge of each thickness was then annealed for 1 hour at 350 °C. Because the wedges varied in thickness across the length, multiple cold work values were able to be recorded. Hardness and thickness measurements were taken before and after the cold rolling and after the annealing as shown in Figure 1. Generally, as cold work increased, hardness increased.
The strongest iron tempered in the fire to make it really hard that’s the kind you see most often shatter.
These protective hand clothing can be availed in a variety of designs. However, most designs include dense thermoplastic pads that provide cushioning to hands, and protects it from vibration, and other impacts. The impact resistant gloves are used in gas and oil industry.
The micro hardness of the prepared samples were obtained by using a Vickers Micro hardness Tester (Model : Leco LV 700, USA). 5 readings were taken for each sample to calculate the average hardness. An indentation load of 5gf was used. After calculating the average hardness for each sample, mean variance and standard deviation (S.D.) was calculated to check the consistency of the data.
This will be the surface material the ball is dropped on. To make the test fair the same people will carry out the same task each time the ball is dropped e.g. the same person drops the ball. The results from the two investigations will then be compared. Risk assessment There are not many risks from dropping a ball but safety must be considered. Theball should not be thrown, and the person dropping the ball should not stand on chairs or tables.
Then, the materials cool down slowly. Through this process, the dislocations of the structure reduce. The strength of materials drop and raise the toughness flexibility and ductility. Also, the nucleation and growth will occurs in annealing.
In order to learn how glass fractures, we must first learn the composition of glass and the different types of glass. Glass is a hard, brittle, amorphous substance composed of sand (silicon oxides) mixed with various metal oxides. When sand is mixed with other metal oxides, melted at high temperatures, and then cooled to a rigid condition without crystallization, the product is glass (Saferstein, 2010). Glass can come in many different forms all of which can range from very brittle glass to bullet proof glass; the stronger the glass, the more ingredients are required and the more complex the process is.
Before I explain and talk about why a ball goes farther when hit with an aluminum bat, I would like to present and explain some vocabulary concept and words. A collision, transfers momentum or kinetic energy from one object to another object. There are two types of collisions, elastic collision and inelastic collision. An elastic collision is a collision that occurs when two objects bounce apart when they collide; the total kinetic energy in the system is the same before and after the collision. For example, elastic collision occurs when equally massive balls move in the same direction; in this case momentum is transferred from one ball to another ball. And an inelastic collision is a collision that occurs when two objects collide and do not bounce away from each other; the collision changes the total kinetic energy in a closed system. For example, inelastic collision occurs when two cars crash and join themselves into one; the objects stick together after colliding. In inelastic collision all that happened is the loss of some kinetic energy, objects don not necessarily need to stick together in an inelastic collision. Whether a collision is an elastic collision or inelastic collision momentum would always be the same before and/or after the collision as long as you have a close system.
Kinetic energy behaves a bit differently depending on the type of collision: elastic or inelastic.
Crumple zones- are a structural feature used in automobiles. They help by absorbing the impact; this is by spreading the impact through parts of the car instead of in the one spot. This reflects back onto law number one, two and three. This is shown when the car hits the object it causes the car to slow down or completely stop (1). The crumble zone would protect the driver because all the energy has been diverted around the car, instead of the one spot. As a result of the cars mass and its acceleration, the force can be calculated (2). When the car crashes it’s most likely that the object w...
Toughness is the ability of a metal to mutilate plastically and to absorb energy in the process before it breaks or fracture. Metals can be heat treated to alter the properties of strength, ductility, toughness, hardness or resistance to corrosion. This can be done by using heat treatment processes which include precipitation strengthening, quenching, annealing and tempering. Annealing and tempering are the most prominent methods for treating metals. A material may become more or less brittle, harder or softer, or stronger or weaker, depending on the treatment used.
Varying characteristics of craters affect the impact it creates. These aspects are the density which is the compactness of an object, (Jones, 2017) the size in regards to diameter, and the height of its fall, (force of impact), of a meteorite. What is the effect of an increased density, size, and/or height of fall of a meteorite on the crater it creates? It is imperative to understand how craters are formed and the characteristics of meteorites that affect their size, in order to predict damage control. If a meteorite is forecasted to hit the Earth at a given time, and its density, size or height of fall (force of impact) are known, the size of its crater can be predicted, allowing for the victim area to prepare for a