scholarly journals Research on Numerical Analysis Technique for Sound Fields Including Perforated Plate (2nd Report, Case in Which Vibro-Acoustic Behavior of Perforated Plate is Considered)

2012 ◽  
Vol 78 (789) ◽  
pp. 1839-1849
Author(s):  
Kazuki TSUGIHASHI ◽  
Toshimitsu TANAKA ◽  
Tatsuhiro KUSAKARI
2019 ◽  
Vol 2019.57 (0) ◽  
pp. 605
Author(s):  
Shunsuke NAKAMURA ◽  
Shinji AKAMATSU ◽  
Yuki MITSUI ◽  
Masaharu NISHIMURA ◽  
Tonau NAKAI ◽  
...  

Author(s):  
F Drabble ◽  
D J Brookfield

Workers in elevated positions must be protected from falling or from the hazardous consequences of falls. Protection from falling can include fences, guard rails, etc., or a restraint system preventing the workers from reaching any point from which they can fall. However, protection from falling can be impractical and in such situations a fall arrest system (FAS) must be provided such that the fall does not cause injury to the worker or to others. This paper surveys prior work on the analysis of FASs including the energy balance method historically used. This method is limited to simple FASs where only one worker may fall. A novel numerical analysis technique for predicting the forces occurring in each component of an FAS during a fall is then described. Results from the numerical analysis are compared with results from experimental tests and with those from the energy balance method. It is shown that the numerical analysis technique predicts forces to within better than approximately 7 per cent, the method being conservative, whereas the errors shown by the energy balance method exceed 26 per cent. The new analysis method is also shown to be applicable to multiple falls.


Author(s):  
Chul-hee Jo ◽  
Kang-hee Lee ◽  
Yu-ho Rho ◽  
Do-youb Kim

Recently, large scale tidal devices have been deployed with a maximum rotor diameter of 20m. These devices impose significant loading on supporting structures. The supporting structure for tidal current power device is under dynamic loadings caused by environmental loadings. Not only the environmental loadings but also the rotating turbine creates dynamic loading as well. The rotating turbine is obviously and continuously deformed for various incoming flow velocities. In many cases, a pile fixed foundation is used to secure the structure. In this study, the commonly used pile fixed type is applied with three blade turbine. A numerical analysis of the hydro-forces from a rotating tidal current turbine to a tower was conducted to determine the deformation distribution along the pile tower. The FSI analysis technique is used in the study.


2022 ◽  
Vol 8 ◽  
pp. 539-550
Author(s):  
Abdul Hamid Ganie ◽  
Abid A. Memon ◽  
M. Asif Memon ◽  
A.M. Al-Bugami ◽  
Kaleemullah Bhatti ◽  
...  

Author(s):  
Fariborz Saghafi ◽  
Afshin Banazadeh

This paper describes a feasibility study of using numerical analysis technique, coupled with a non-linear simulation model of a conceptual fluidic-thrust-vectored unmanned aerial tail-sitter to obtain required thrust deflection angles for a transition manoeuvre in take-off. It also studies the aircraft behaviour in transition subjected to the changes in specified parameters like the thrust value and the engine distance from the centre of gravity. The focus of the research presented was to get the vehicle from zero speed on the ground, in vertical position, to a specified velocity at a specified attitude, in cruise position. It was also specified that, when the vehicle was considered to be flying, it should not reduce speed or be descending and that its angle of attack should remain within a reasonable bound, since extreme angle of attack region causes the simulation and analysis to fall in the uncertain zone. The aircraft pitch attitude was also specified to decrease steadily in every integration step regarding the aircraft velocity. The transition problem was mathematically constructed and coded into Matlab/Simulink for the purpose of analysis and simulation. The inputs to the simulation program were simply series of thrust deflection angles at a number of different instants of time. Simulation was performed for a constant vehicle configuration. It was found that transition was feasible for the thrust to weight ratio around 1.0947 and it took 15 seconds to accomplish, while no attempt was made for time optimization.


2018 ◽  
Vol 792 ◽  
pp. 16-22
Author(s):  
Kritsana Thummikanonth ◽  
Pairoj Sapsamanwong ◽  
Apirath Gositanon ◽  
Thawatchai Boonluang

In manufacturing process of rocket components, quenching and tempering process can be used to achieve suitable hardness, ultimate tensile strength and yield strength of raw material. The trial and error of quenching and tempering process to succeed suitable properties of raw material will waste of budget and time. In this study, numerical analysis of quenching and tempering process on AISI 4130 steel was investigated comparative to actual heat treatment process to evaluate the agreement between them. The numerical analysis technique was used to seek suitable tempering temperature with specify quenching temperature at 870°C and soaking time for an hour. The result showed that suitable tempering temperature was 450°C to achieve as-required mechanical properties. The actual quenching and tempering process was performed by furnace heating to 860°C and soaking for 60 minutes, followed by 450°C tempering for 2 hours. The results will be comparatively concluded that they slightly differed from numerical analysis around 5%-12% and showed a good agreement between numerical analysis and experimental result.


1996 ◽  
Vol 12 (04) ◽  
pp. 269-275
Author(s):  
Panagiotis Michaleris ◽  
Andrew DeBiccari

This paper presents an efficient and effective numerical analysis technique for predicting welding-induced buckling. The technique combines three-dimensional structural analyses with two-dimensional welding simulations. Implementation of the technique can determine the appropriate welding conditions under which the design critical buckling load is not exceeded. Experimental results obtained from small-and large-scale mock-up panels are used to confirm the predictions of the analytical models, The paper concludes with a study of the effects of heat input (weld size), panel size, and panel thickness on buckling distortion.


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