Energy Similitude Correction Method for Free Vibration of Cylinders

2020 ◽  
pp. 2150023
Author(s):  
Lilin Zhou
Keyword(s):  
Free Vibration ◽  
Wall Thickness ◽  
Correction Method ◽  
Scale Model ◽  
Thickness Variation ◽  
Numerical Examples ◽  
Scale Models ◽  
Wall Thickness Variation ◽  
Similitude Theory

Similitude theory has been applied to design scale models in many fields of engineering. As for free vibration of cylinders, the wall thickness is too thin to manufacture scale model, which leads to similitude distortion. The aim of this study is to correct the similitude distortion and establish the distorted similitude relationship for free vibration of cylinders. First, the complete and partial similitude relationships are deduced while the similitude distortion of wall thickness is discussed. Then, with analysis of similitude for energy, an equation with prediction of modal frequencies for prototype is established and the energy similitude correction method is proposed. Finally, through numerical examples, this method is verified and the influence of wall thickness variation on the accuracy of the proposed method is analyzed.

Mechanics of Conventional Spinning

1963 ◽  
Vol 85 (4) ◽  
pp. 346-350 ◽  
Author(s):  
H. C. Sortais ◽  
S. Kobayashi ◽  
E. G. Thomsen
Keyword(s):  
Wall Thickness ◽  
Pure Aluminum ◽  
Tangential Force ◽  
Deformation Energy ◽  
Thickness Variation ◽  
Force Component ◽  
Commercially Pure ◽  
Conventional Spinning ◽  
Wall Thickness Variation ◽  
Experimental Values

In conventional spinning of cones, the cone-wall thickness variation was studied using blanks of 1100-0 commercially pure aluminum sheet of 0.050-in. thickness. The results revealed that the radial stress induced in the unspun flange is the major cause of nonuniform wall thickness of spun cones. The theoretical tangential force component was derived by use of the deformation energy method. Qualitative agreement was found between the theoretical and the experimental values of tangential force component in the underspinning conditions.

Injection-Moulded Models of Major and Minor Arteries: The Variability of Model Wall Thickness Owing to Casting Technique

2005 ◽  
Vol 219 (5) ◽  
pp. 381-386 ◽  
Author(s):  
T O'Brien ◽  
L Morris ◽  
M O'Donnell ◽  
M Walsh ◽  
T McGloughlin
Keyword(s):  
Wall Thickness ◽  
Ccd Camera ◽  
Western Society ◽  
Experimental Investigations ◽  
Thickness Variation ◽  
Casting Technique ◽  
Radiological Images ◽  
Thickness Variability ◽  
Wall Thickness Variation ◽  
Integrated Technique

Cardiovascular disease of major and minor arteries is a common cause of death in Western society. The wall mechanics and haemodynamics within the arteries are considered to be important factors in the disease formation process. This paper is concerned with the development of an efficient computer-integrated technique to manufacture idealized and realistic models of diseased major and minor arteries from radiological images and to address the issue of model wall thickness variability. Variations in wall thickness from the original computer models to the final castings are quantified using a CCD camera. The results found that wall thickness variation from the major and minor idealized artery models to design specification were insignificant, up to a maximum of 16 per cent. In realistic models, however, differences were up to 23 per cent in the major arterial models and 58 per cent in the minor arterial models, but the wall thickness variability remained within the limits of previously reported wall thickness results. It is concluded that the described injection moulding procedure yields idealized and realistic castings suitable for use in experimental investigations, with idealized models giving better agreement with design. Wall thickness is variable and should be assessed after the models are manufactured.

Study on Three-Way Pipe’s Internal High Pressure Forming Simulation

2013 ◽  
Vol 589-590 ◽  
pp. 517-522
Author(s):  
Shi Gang Wang ◽  
Fu Sheng Gao ◽  
Feng Lan Cheng ◽  
Qiang Guo
Keyword(s):  
High Pressure ◽  
Wall Thickness ◽  
Three Dimensional ◽  
Thickness Variation ◽  
Forming Simulation ◽  
Finite Element Software ◽  
Plastic Processing ◽  
Wall Thickness Variation ◽  
Dimensional Shape ◽  
Pressure Parameter

Internal high pressure forming is a kind of the modern plastic processing technology. Using liquid as the pressure transmitting medium, explore the effect of internal high pressure parameter on the three passing pipe technique, internal high pressure forming technique is applied on the three-dimensional shape parts deformation. In this study, we simulate the three-way pipe process by finite element software, analyze the forming force influence to the tube forming quality and get the changeable regulation of the pipe wall thickness with conclusion of the wall thickness variation, which provides the reference data and guidance for the actual production of the three-way pipe.

scholarly journals A Design Approach of Porthole Die for Flow Balance in Extrusion of Complex Solid Aluminum Heatsink Profile with Large Variable Wall Thickness

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 553
Author(s):  
Tat-Tai Truong ◽  
Quang-Cherng Hsu ◽  
Van-Canh Tong ◽  
Jinn-Jong Sheu
Keyword(s):  
Wall Thickness ◽  
Metal Flow ◽  
Die Design ◽  
Design Approach ◽  
Thickness Variation ◽  
Extrusion Force ◽  
Bridge Structure ◽  
Flow Balance ◽  
Porthole Die ◽  
Wall Thickness Variation

In this study, porthole die used for extrusion of a solid heatsink profile with wall thickness variation ratio up to 15.3 was designed using finite element (FE) simulations. To improve the flow balance in the die, a design approach was introduced to find the appropriate die structure, which includes the porthole and pocket geometry correction, the bearing length adjustment, and the port bridge structure modification. Using the proposed die, the predicted velocity relative difference (VRD) and the maximum velocity difference (ΔV) of extrudate were significantly lower than those of an initial die, which was preliminarily designed based on general design experiences. The required extrusion force and the residual stress in the product were also reduced significantly. Then, the effects of the port bridge structure and welding chamber height on the behavior of the metal flow in the die were investigated. To verify the proposed die design, experimental extrusions were conducted on a 930-ton extruder. The experiment results showed that the extruded product fulfilled the requirements for dimensional tolerances. The design approach presented in this paper can be useful for practical implementation of die design when extruding similar solid heatsink profiles with large wall thickness variation.

Reduction in longitudinal wall-thickness variation on tubes rolled on TPA-140 longitudinal rolling mills at the Sinarskii Pipe Plant

Metallurgist ◽  
1986 ◽  
Vol 30 (8) ◽  
pp. 293-294
Author(s):  
M. B. Bisk ◽  
A. I. Brizhan ◽  
G. A. Kaspirovich ◽  
A. I. Nechiporenko ◽  
Yu. I. Pustovoichenko ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Thickness Variation ◽  
Pipe Plant ◽  
Longitudinal Rolling ◽  
Rolling Mills ◽  
Longitudinal Wall ◽  
Wall Thickness Variation
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