124 research outputs found
Numerical analysis on materials energy absorbing capability under gravity loading impact
Energy absorbers are systems that convert kinetic energy into other forms of energy, such as pressure energy in compressible fluids, elastic strain energy in solids, and plastic defonnation energy in defom1able solids. The process of conversion for plastic defonnation depends, among
other factors, on the magnitude and method of application of loads, transmission rates, defonnation displacement pattems, and material properties. The applications of defonnable energy absorbers have been paid serious attention for several decades, for the means of safety.
The aim is to minimize the impact by controlling the deceleration pulse during impact, i.e. extending the period of dissipation of kinetic energy. Cushioning devices on vehicle bumpers, crash retarders in emergency systems of lifts, and some crash barriers used as road blocks are
everyday examples. The vital application of this work is reliability of energy to absorb massive landing force, for instance the missile safeguards when landing on the ground. The high energy absorbing ability can practically applied into rocket system for sending the chips or any other
important materials to the space or far-distant place, thus protecting the chips from damag
Experimental results of pipe whip impact
Pipe whip is a safety related issue for nuclear power and chemical plants, where pipes are often used to transport fluids at high pressure and high temperature. Experiment works for empty pipe and liquid filled pipe are needed in this study. The model was made of simple pipe whip system which enables the missile pipe to hit the target pipe at an angle of 90ยฐ and also 55ยฐ oblique impact. The results
of the experiments show the possible damage and failure of different types of pipe whip with different fill
conditions.
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Simulation setup of pipe whip impact
The safety of pipe whip is related issue for nuclear power and chemical plants, where pIpes are often used to transport fluids at high pressure and high temperature. Simulation analysis for empty pipe and liquid filled pipe are conducted in this study. The model was made of simple pipe whip system which enables the missile pipe to hit the target pipe at an angle of 90ยฐ and also 55ยฐ oblique impact. The simulation setup is done by LS-DYNA which is an
developed by the Livennore Software Technology Corporation (LSTC). It is a highly nonlinear transient dynamic finite element analysis using explicit time integratio
Simulation results of pipe whip impact at 55ยฐ angle
The safety of pipe whip is related issue for nuclear power and chemical plants, where pIpes are often used to transport fluids at high pressure and high temperature. Simulation analysis for empty pipe and liquid filled pipe are conducted in this study. The model was made of simple pipe whip system which enables the missile pipe to hit the target pipe at an angle of 55ยฐ oblique impact. The simulation setup is done by LS-DYNA which is highly nonlinear transient dynamic finite element analysis using explicit time integration. The results show the
defonnation occurred in the pipe whip at different degrees of impact
Experimental results of liquid slosh in a cylindrical tank with different fill levels
The fundamental properties of slosh could be effectively investigated through laboratory experiments under controlled conditions. Such experiments can provide considerable insight into the fluid slosh and associated forces and moments. The nlajority of the experimental investigations on the fluid slosh have been conducted in model tanks which are small in size compared to the full scale tanks of cross-section area in the order of 3.5 mn2. The cross-sectional areas of the model tanks employed in the
reported studies were in the order of 0.2 m' [I-31. Since the similarity of sloshing fluid flows is very complex, the slosh behavior would be expected to differ for different tank sizes. Moreover, some of the reported slosh studies were limited to measurements of hydrodynamic pressure at given points or only one component of the slosh forces. The stability of a road tank vehicle, however, is strongly dependent on the resultant slosh forces and moments arising in all the translational and rotational axe
Simulation results of pipe whip impact at 90ยฐ angle
The safety of pipe whip is related issue for nuclear power and chemical plants, where pIpes are often used to transport fluids at high pressure and high temperature. Simulation analysis for empty pipe and liquid filled pipe are conducted in this study. The model was made
of simple pipe whip system which enables the missile pipe to hit the target pipe at an angle of 90ยฐ angle. The simulation setup is done by LS-DYNA which is highly nonlinear transient dynamic finite element analysis using explicit time integration. The results show the defol1nation
occurred in the pipe whip at different degrees ofimpact
Finite element to predict damage of a polycarbonate armor plate subjected to impact
Numerical studies on the response of annor systems made up of PC and PMMA were reported [1] where smooth particle hydrodynamics (SPH) was used to simulate the response of
PC and PMMA layers and it has been found that many existing material models can reproduce a close range results at the initial stage of simulations. Further numerical results based upon the experiments [2] have been reported by [3] where the effects of varying support configurations
have been investigated on the plastic failure of the circular steel plates. Circular plates subjected to dense fragment cluster impact [4, 5] investigates the failure process of almor plates subjected to a fragment cluster consisting of many projectiles impacting the plate simultaneously. Test results indicate that the impulse and the rate of energy deposition on the target and the impacting duration ofthe ti-agment cluster are the most important factor
Numerical and experimental results of liquid slosh in a partially filled cylindrical tank
Several experiments with different water levels were conducted to monitor the effect of water slosh in the container tank. This experimental study on fluid slosh was conducted to validate the results of the numerical models. The observation of the experimental results shows that strain gage-1 experienced compression strain at the top of the tank, while strain gage-2 experienced tension strain at the frontal area. The unit of the strain is displayed in pdm. From this experiment, the values for strain gage-1 is quite lower than strain gage-2.This big different is due to strain gage-2 in the frontal area is experience more
forces and moments compared to the strain gage- 1 at the top of the tank
Experimental setup of pipe whip impact
Pipe whip is a safety related issue for nuclear power and chemical plants, where pipes are often used to transport fluids at high pressure and high temperature. Experiment works for empty pipe and liquid filled pipe are needed in this study. The model was made of simple pipe whip
system which enables the missile pipe to hit the target pipe at an angle of 90ยฐ and also 55ยฐ oblique impact. The possible damages occur on the target pipe when the missile pipe hit it at certain velocity depend on the different mass of dropper and different diameter ofthe target pipe.
Copper pipe is used as the target pipe and steel as the missile pip
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