The Split Hopkinson Pressure Bar is named after Bertram Hopkinson [2], who in 1914 acquired a technique to evaluate the pressures created by dynamic events such as the blast caused by a rifle bullet or the explosion of explosives. In this placement, a long cylindrical bar of steel is suspended horizontally by four equal threads so that it can dangle in the vertical plane parallel to it. A short piece of rod of the same diameter is obtained against the long bar by magnetic attraction created by a solenoid. A rifle bullet is forced out or gun cotton is detonated near the close of the long bar. This creates a pressure wave which goes from the long bar in the short piece of rod. On passing the loose end of the short rod the pressure wave is reflected back as a tensile wave; when the magnitude of the tensile wave exceeds that of the pressure wave at the butted end of the short rod, the inability of the short rod to hold up the tension along the joint produces separation and it flies away. The little rod is caught in a box suspended in …show more content…
There were fears about whether the value of surface strain measured by the strain gages was equal to the genuine distribution of air throughout the cross-section of the legal profession. Cunningham and Goldsmith [6] compared the forces measured by strain gages to those received by piezoelectric quartz crystals embedded between two similar bars. The results indicated excellent understanding between both methods. Krafft et al. [7] were the first to use strain gages in the Split Hopkinson Pressure bar. A schematic of the SHPB facility used in the present work is presented in Figure 2.1. The Split Hopkinson Pressure Bar consists of an incident bar, transmission bar and a projectile termed as the striker bar all made of maraging steel which holds a nominal yield strength of 2500
Morton-Thiokol Inc. had engineered the space shuttle's solid rocket booster (SRB) based on the Air Force's Titan III design because of its reliability. The SRB's steel case was divided into segments that were joined and sealed by rubber O-rings. Although the Titan's O-rings had occasionally been eroded by hot gases, the erosion was not regarded as significant. A second, redundant O-ring was added to each joint to act as back-up should the primary O-ring failed.
Melton, Jack W. and Lawrence E. Pawl. “Basic Facts Concerning Artillery.” Civil War Artillery. 2009. 17 January 2010. .
Materials: C-clamps, inertial scale, a watch with a second hand, and a triple beam balance.
It could be triggered by pulling trip wires or having been pressure activated. It was gunpowder, fuse, and detonation caps in iron containers that were sometimes thought of as unethical by numerous people.
One of the most influential engineering discoveries in the past century was the ill-fated Tacoma Narrows Bridge. “Galloping Gertie” as she was known to local residents, the massive Washington state suspension bridge shook, rattled and rolled its way into the history books. Legendary in its time, the Tacoma Narrows Bridge held many records and drew tourists from around the world in its short life. However, the famous bridge is not known for its creative engineering or speedy construction, unfortunately the bridge was destined to fail. That failure in turn changed the way every building is constructed today as well as further man’s understanding of physics and the forces of nature. In this paper we will examine the history of the Tacoma Narrows Bridge from design to construction, the failure of the bridge, and ultimately the rebuilding project.
Pear, Tom Hatherly and Grafton Elliot Smith. Shell Shock and its Lessons. First Edition. England: Manchester University Press, 1917. http://www.vlib.us/medical/shshock/index.htm (assessed February 10, 2012).
This law, known as Gay-Lussac’s law, observes the relationship between the pressure and temperature of a gas. Contrary to its name, this relationship was actually discovered by French scientific instrument inventor and physicist Guillaume Amontons, and is occasionally referred to Amontons’ Law of Pressure-Temperature. While Guy-Lussac did explore the temperature-pressure relationship, Guy-Lussac’s law is usually used to refer to the law of combining volumes. Amontons stubble across this relationship when he was building an “air thermometer.” Although not many have been able identify his exact method of experimentation, later scientist developed an apparatus in which consisted of pressure gauge and a metal sphere. These two pieces were then attached and submerged in solutions of varying temperatures. From Amontons’ and Guy-Lussac’s research and experimentation, they determined that pressure and volume had direct relationship; as one increased, the other increased. The quotient of pressure and temperature was then found to equal a constant, in which just like Boyle’s law, could be used to find one of the two variables at another pressure or temperature, given one of the variables and that the other conditions remain the same. Instead of using various solutions at different temperatures like in the experiment describe above, many experiments today utilize a solution in which the temperature is increased or decrease, such as in the following
The one that he describes next is peer pressure. He stated how peer pressure is intertwined with
During the years, there have been many bridge that have collapsed, causing many lives to be put in danger and lost. This project is to determine how much weight it would take for different scale model designs of truss bridges to collapse when weight, pressure, and gravity is applied to them. This experiment will test which truss bridge designs of, Pratt, Warren, and Howe. I chose this project because I want to see which truss bridge could hold the most weight capacity.
His comparison was based on a visible flaw in the bullet which was traced back to a mold Rudin, Inman (2002) A huge part of the criminal investigations that deal with weapons like type of guns is where the study of ammunition ballistics comes into play. According to Sapp (2006) Just as there are many different types of weapons, there exist a plethora of different types of ammunition. Some weapons use one type of ammunition, while other guns are capable of handling several different types. Each of these different types is configured to accomplish a specific task. All in all, it is important to know the purpose of and the correct type of ammunitions used by each of weapon. Ammunition ballistics has been only growing ever since then first study. When studying a bullet, the real results to find which specific gun it comes from is found in the design of the bullet, which can be found in three variants of shapes, the composition of what the bullet is made out of, and the biggest indicator, the barrel of the gun used. As it turns out, the barrel is the most guaranteed method to finding the exact gun being searched for in a study, as every bullet has the same materials, and designs, the barrel will tell you which gun the bullet was fired from by the markings on the shot bullet known as striated
The very idea of flying through the air at 15-19 feet just to clear a little bar scares some people to death. Maybe even more if the only thing that you have to hold onto is a little piece of plastic. The purpose of this paper is to help put some of these fears to rest from the point of view of physics.
Further study is made and Sir Isaac Newton made his Second Law which allows calculating pressure req...
From the first-hand experience obtained from the experiment, further understanding has been provided. By doing the hammer test, the strength of the metal can be identified and the quality of welded metals was also assessed. In can also be concluded that the second sample has much better quality than the first sample from the hammer test and visual inspection. All in all, a good travel speed, current and arc gap must be present in order to produce a good weld of metals.
This device was consequential to mechanical philosophy because it was an attempt by Boyle to explain the underlying nature of the vacuum. Boyle was attempting to understand and reproduce the results of a Torticillian vacuum. In 1643, Evangelista Torricelli found an empty space in a sealed glass tube above the mercury in his newly invented barometer. Philosophers across Europe tried to devise ways of establishing the properties of a ‘Tortecellian vacuum'. To investigate this new and conspicuously instrument-generated phenomenon of nature, however, it would have to be necessary to make a vacuum that was physically larger and more accessible than that inside a barometer. Mechanical philosophy pervaded every aspect of Boyle's work on the air pump, even his descriptions, which he elucidated in his 1660 work entitled New Experiments Physico-Mechanical, Touching the Spring of the Air, and its Effects. In it he states: Your Lordship will easily suppose, that the notion I speak of is, that there is a spring, or elastical power in the air we live in. By which… spring of the air, that which I mean is this: that our air either consists of, or at least abounds with, parts of such nature, that in case they be bent, and as soon as those bodies are removed or reduced to give them way." Margaret C. Jacob, The Scientific Revolution: A Brief History with Documents (Basingstoke: Palgrave Macmillan, 2010),