Finite element modelling of the thermal stress field during processing of VLSI multilevel structures

1998 ◽  
Vol 34 (5) ◽  
pp. 471 ◽  
Author(s):  
P.M. Igic ◽  
P.A. Mawby
Author(s):  
Christopher M. Gill ◽  
Paul Hurrell ◽  
John Francis ◽  
Mark Turski

This paper describes the design optimisation of an SA508 ferritic steel ring weld specimen using FE modelling techniques. The aim was to experimentally and analytically study the effect of post weld heat treatment upon a triaxial residual stress field. Welding highly constrained geometries, such as those found in some pressure vessel joints, can lead to the formation of highly triaxial stress fields. It is thought that application of post weld heat treatments will not fully relax hydrostatic stress fields. Therefore a ferritic multi-pass ring weld specimen was designed and optimised, using 2D finite element modelling, to generate a high magnitude triaxial stress field. The specimen thickness and weld-prep geometry was optimised to produce a large hydrostatic stress field and still allow efficient use of neutron diffraction to measure the residual stress. This paper reports the development of the test specimen geometry and compares the results of welding FE analysis and neutron diffraction measurements. Welding residual stresses were experimentally determined using neutron diffraction; both before post weld heat treatment. Three dimensional moving heat source weld finite element modelling has been used to predict the residual stresses generated by the welding process used. Finite element modelling examined the effect of phase transformation upon the residual stress field produced by welding. The relaxation of welding stresses by creep during post weld heat treatment has also been modelled. Comparisons between the modelled and measured as-welded residual stress profiles are presented. This work allows discussion of the effect of post weld heat treatment of triaxial stress fields and determines if finite element modelling is capable of correctly predicting the stress relaxation.


2011 ◽  
Vol 117-119 ◽  
pp. 97-100
Author(s):  
Jun Ci Cao ◽  
Rong Chao Qian ◽  
Wei Li Li

3kW two poles induction motor with compound cage rotor is illustrated in this paper, and 2-D thermal stress field of induction motor rotor is calculated and analyzed by finite element. Contrasting with common induction motor, induction motor with compound cage rotor has specific rotor shot shape and the bar is comprised of the upper compound material and the lower cast aluminium, which cause distribution of thermal stress is special. The motor with the rotor shot of compound material laid at single site is chosen to analyzing. The maximum thermal stress in the bar is calculated at different load, and the distribution of thermal stress in the bar is analyzed at rate load. The law of distribution of thermal stress in the bar has same reference value for designing new type of induction motor.


Solid Earth ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 2515-2533
Author(s):  
Silvia Massaro ◽  
Roberto Sulpizio ◽  
Gianluca Norini ◽  
Gianluca Groppelli ◽  
Antonio Costa ◽  
...  

Abstract. In recent decades, finite-element modelling (FEM) has become a very popular tool in volcanological studies and has even been used to describe complex system geometries by accounting for multiple reservoirs, topography, and heterogeneous distribution of host rock mechanical properties. In spite of this, the influence of geological information on numerical simulations is still poorly considered. In this work, 2D FEM of the Colima Volcanic Complex (Mexico) is provided by using the Linear Static Analysis (LISA) software in order to investigate the stress field conditions with increasingly detailed geological data. By integrating the published geophysical, volcanological, and petrological data, we modelled the stress field considering either one or two magma chambers connected to the surface via dykes or isolated (not connected) in the elastic host rocks (considered homogeneous and non-homogeneous). We also introduced tectonic disturbance, considering the effects of direct faults bordering the Colima Rift and imposing an extensional far-field stress of 5 MPa. We ran the model using the gravity in calculations. Our results suggest that an appropriate set of geological data is of pivotal importance for obtaining reliable numerical outputs, which can be considered a proxy for natural systems. Beside and beyond the importance of geological data in FEM simulations, the model runs using the complex feeding system geometry and tectonics show how the present-day Colima volcanic system can be considered in equilibrium from a stress state point of view, in agreement with the long-lasting open conduit dynamics that have lasted since 1913.


2013 ◽  
Vol 444-445 ◽  
pp. 1422-1426
Author(s):  
Li Zi Chen ◽  
Chun Yuan Jing ◽  
Xiao Wei Guan

Based on the theory of the thermal conduction and the thermal elastic equations, does some researches in view of the thermal Damage of K9 glass by finite element analysis. The distribution of temperature field and thermal stress field of the ideal K9 glass which irradiated by 100W pulsed-Nd: YAG laser are simulated with finite element software. The result shows that the temperature of the surface of glass doesnt reach the melting and the thermal stress of it doesnt get to the requirement for fracture strength. Then, the model of K9 glass containing inclusions has be built. The simulation result indicates that inclusions may affect the distribution of temperature field and thermal stress field of the K9 glass, which makes the injected laser beams energy centralize on a small area around the inclusions owing to the existence of the strong absorbing, thus leading to K9 glass laser damage threshold reduction and easier to thermal damage.


Sign in / Sign up

Export Citation Format

Share Document