Behavior of Pipe Flange Connection in Transient Temperature Field

1993 ◽  
Vol 115 (2) ◽  
pp. 142-146 ◽  
Author(s):  
T. Sawa ◽  
T. Hirose ◽  
H. Kumano
Keyword(s):  
Thermal Conduction ◽  
Room Temperature ◽  
Maximum Stress ◽  
Transient Temperature ◽  
Strain Gages ◽  
Bolted Connection ◽  
Transient Temperature Field ◽  
The Difference ◽  
Transient Thermal ◽  
Steel Bolts

The behavior of a bolted connection, using several aluminum alloy pipe flanges with steel bolts and nuts, was examined under the condition of thermal conduction. Using the finite difference method, temperature distributions in the connection subjected to transient thermal conduction were analyzed. A method for obtaining an increment in axial bolt force and the maximum stress produced in the bolts was demonstrated. In the experiments, the temperature distribution in the connection was measured by use of thermocouples. In addition, both the increment and the maximum stress due to the difference in coefficients of linear expansion as well as the stress produced in the hub were measured by strain gages when the inner circumference of the pipe flanges was subjected to thermal conduction and the outer circumference was kept at room temperature. The analytical results were fairly consistent with the experimental ones.

Behavior of a Tapered Hub Flange With a Bolted Flat Cover in Transient Temperature Field

1996 ◽  
Vol 118 (1) ◽  
pp. 115-120 ◽  
Author(s):  
T. Sawa ◽  
T. Hirose ◽  
Y. Nakagomi
Keyword(s):  
Thermal Condition ◽  
Thermal Loading ◽  
Transient Temperature ◽  
Strain Gages ◽  
Bolted Connection ◽  
Transient Temperature Field ◽  
Bolt Stress ◽  
Transient Thermal ◽  
Flat Cover ◽  
Steel Bolts

An experimental and analytical study was made on a bolted connection subjected to thermal loading. The connection consists of an aluminum alloy tapered hub flange and a flat cover, including a gasket fastened by steel bolts and nuts. Temperature distribution in the connection was measured with thermocouples, and the axial bolt force, the maximum bolt stress, and the hub stress were measured by strain gages under a thermal condition that theinner surface of the flanges was heated and the outer surfaces of the flanges and the cover were held at room temperature. Finite difference analysis was made to obtain the temperature distributions in the connection due to a transient thermal condition. This paper demonstrates the method for obtaining an increment in axial bolt force and the maximum bolt stress. In all cases, the analytical results were fairly consistent with the experimental results.

Modal Analysis of Wing Considering Transient Thermal Effects

2013 ◽  
Vol 444-445 ◽  
pp. 1400-1406 ◽  
Author(s):  
Hao Liu ◽  
Xia Sheng Sun ◽  
Xiao Dong Li
Keyword(s):  
Modal Analysis ◽  
Thermal Environment ◽  
Temperature Gradients ◽  
Large Temperature ◽  
Aerodynamic Heating ◽  
Transient Temperature ◽  
Transient Temperature Field ◽  
Vehicle Structure ◽  
Wing Structure ◽  
Transient Thermal

The severe aerodynamic heating on the surface of modern hypersonic flight vehicle, that can bring high temperature and large temperature gradients in the structure of the vehicle, will be a challenge for the vehicles design and multidisciplinary optimization. The transient thermal environment consists of high temperature and large temperature gradients will generate two important problems related to vehicle structure, namely: 1) the material property, such as elastic modulus, will be degraded at elevated temperature, and 2) the non-uniform thermal stress cased by large temperature gradients will change the stiffness distribution of wing structure, which can make the modal frequencies and shapes of structure changed remarkably. Firstly, the theory and methodology of structure modal analysis in transient thermal environment is outlined. Subsequently, the transient temperature field of structure considering aerodynamic heating is obtained by employing computational technology of aerodynamic heating/structure heat transfer coupling program. Finally, the modal frequencies and shapes of vehicle structure under transient temperature field is calculated based on finite element method (FEM). Based on the analysis and investigation of the simulation results, the influence of the transient thermal environment on structure modal frequency and shape is determined. Furthermore, the investigation of wing structure modal analysis considering aerodynamic heating is an important basis of aerothermoelastic simulation.

Simulation on Grind-Hardening Residual Stress Field of 48MnV Steel

2012 ◽  
Vol 499 ◽  
pp. 301-306 ◽  
Author(s):  
Shu Sheng Li ◽  
Bing Xiao ◽  
H.H. Su ◽  
S.L. Gong
Keyword(s):  
Residual Stress ◽  
Temperature Field ◽  
Residual Stress Distribution ◽  
Transient Temperature ◽  
Thermal Source ◽  
Residual Stress Field ◽  
Transient Temperature Field ◽  
Grind Hardening ◽  
The Difference ◽  
Grinding Hardening

By using ANSYS, the temperature distribution in workpiece of steel 48MnV under the actions of a moving thermal source, is first carried out by FEM for non-linear transient temperature field. On this basis, the residual stress distribution in the workpiece under the action of temperature variation and moving grinding loads is determined by FEM for thermo elastic-plasticity. The result shows that the existent residual stress on surface of grinding hardening is press. The reason of this is discussed. The difference between the simulated value and measured value of grind-hardening stress is acceptable.

Influences of New Electrical Material on Transient Heat Transfer in IMCCR

2011 ◽  
Vol 291-294 ◽  
pp. 1669-1673
Author(s):  
Jun Ci Cao ◽  
Wei Li Li ◽  
Xiao Chen Zhang ◽  
Yi Huang Zhang
Keyword(s):  
Induction Motor ◽  
Motor Performance ◽  
Heat Diffusion ◽  
Transient Temperature ◽  
Thermal Coupling ◽  
Analysis Method ◽  
Transient Temperature Field ◽  
Transient Thermal ◽  
Cage Rotor ◽  
Material Permeability

A new kind of alloy (conductor for electric and magnetic), is proposed in this paper, which applied in induction motor rotor bars, and a kind of induction motor with compound cage rotor(IMCCR) is obtained. By using the electromagnetic-thermal coupling analysis method, the transient temperature field of an IMCCR is numerically analyzed, and the transient thermal process of motor operating with blocked rotor for 10s and then stopped for 10min natural cooling is calculated. The heat diffusion of stator equivalent windings and the double-directions heat transmission processes in stator are analyzed. Based on which, the influences of rotor material permeability and conductivity on motor performance are studied. Comparing with the normal nonmagnetic material, the alloy could improve motor performance significantly while ensure motor thermal performance, which indicates the wide application of such alloy in electrical machines.

Transient Temperature During the Vaporization of Liquid on a Pulsed Laser-Heated Solid Surface

1996 ◽  
Vol 118 (3) ◽  
pp. 702-708 ◽  
Author(s):  
H. K. Park ◽  
X. Zhang ◽  
C. P. Grigoropoulos ◽  
C. C. Poon ◽  
A. C. Tam
Keyword(s):  
Thin Film ◽  
Solid Surface ◽  
Elevated Temperatures ◽  
Bubble Nucleation ◽  
Transient Temperature ◽  
Specular Reflectance ◽  
Transient Temperature Field ◽  
Excimer Laser Pulse ◽  
Nanosecond Time Resolution ◽  
Laser Heated

The thermodynamics of the rapid vaporization of a liquid on a solid surface heated by an excimer laser pulse is studied experimentally. The transient temperature field is measured by monitoring the photothermal reflectance of an embedded thin film in nanosecond time resolution. The transient reflectivity is calibrated by considering a temperature gradient across the sample based on the static measurements of the thin film optical properties at elevated temperatures. The dynamics of bubble nucleation, growth, and collapse is detected by probing the optical specular reflectance. The metastability behavior of the liquid and the criterion for the onset of liquid–vapor phase transition in nanosecond time scale are obtained quantitatively for the first time.

scholarly journals Transient thermal conduction with variable conductivity using the Meshless Local Petrov–Galerkin method

2016 ◽  
Vol 272 ◽  
pp. 676-686 ◽  
Author(s):  
N.P. Karagiannakis ◽  
G.C. Bourantas ◽  
A.N. Kalarakis ◽  
E.D. Skouras ◽  
V.N. Burganos
Keyword(s):  
Galerkin Method ◽  
Thermal Conduction ◽  
Transient Thermal ◽  
Variable Conductivity

Investigation on endurance evaluation of a portal crane: experimental, theoretical and finite element analysis

2020 ◽  
Vol 62 (4) ◽  
pp. 357-364
Author(s):  
Yusuf Aytaç Onur ◽  
Hakan Gelen
Keyword(s):  
Finite Element ◽  
Critical Points ◽  
Maximum Stress ◽  
Strain Gages ◽  
Finite Element Analyses ◽  
Element Analysis ◽  
Element Simulation ◽  
Main Girder ◽  
Stressed Component ◽  
Portal Crane

Abstract In this study, the stress on portal crane components at various payloads has been investigated theoretically, numerically and experimentally. The portal crane was computer-aided modeled and finite element analyses were performed so that the most stressed points at the each trolley position investigated on the main girder could be determined. In addition, the critical points were marked on the portal crane, and strain gages were attached to the those critical points so that stress values could be experimentally determined. The safety factor values at different payloads were determined by using finite element simulation. Results indicate that the most stressed component in the examined portal crane is the main girder. Experimental results indicate that the maximum stress value on the main girder is 3.05 times greater than the support legs and 8.99 times larger than the rail.

Effect of titanium alloys elasticity modulus on warping of stamped blanks during cooling

2021 ◽  
pp. 221-227
Author(s):  
M.O. Smirnov ◽  
A.M. Zolotov ◽  
A.M. Tyukhtyaev
Keyword(s):  
Mathematical Modeling ◽  
Titanium Alloys ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Elasticity Modulus ◽  
Preliminary Deformation ◽  
Wide Spread ◽  
Temperature Dependences ◽  
Cumulative Deformation ◽  
The Difference

Wide spread in the values of the elasticity modulus of the titanium VT6 alloy and its analogs Ti—6Al—4V, Ti—6Al—4V ELI at room temperature and at elevated temperatures is revealed аs result of the literature sources analysis. The data are ambiguous, the available temperature dependences of the elasticity modulus have very different values starting from the temperature T l 500 °C. Mathematical modeling of the warping process is carried out on the example of figurine-shaped stamped blank of turbine blade using various dependences of the elasticity modulus on temperature. Cases of warping during cooling of stamped blank after cooling-down in stamp with and without cumulative deformation are considered. The difference in the course of thermal deformations during the cooling of the workpiece is obtained using different temperature dependences of the elasticity modulus. The presence of preliminary deformation increases the warping of the workpieces.

Sign in / Sign up

Export Citation Format

Share Document