Design of Skirt to Cone Joint in Coke Drum: A Parametric Approach Based on Fatigue Analysis

2011 ◽  
Author(s):  
M. Sohel M. Panwala ◽  
S. L. Jaiswal
Keyword(s):  
Fatigue Life ◽  
Thermal Fatigue ◽  
Parametric Study ◽  
Variable Temperature ◽  
Great Influence ◽  
Analysis Tool ◽  
Element Analysis ◽  
Higher Temperature ◽  
Temperature And Pressure ◽  
Transient Thermal

Coke Drums are critical equipment in refineries due to variable temperature and pressure. The temperature is highly fluctuating which causes the thermal fatigue in coke drums. The phenomenon of this thermal fatigue plays a very crucial role in failure of coke drums. In the present study, a coke drum is subjected to pressure - temperature reversal with each cycle of 48 hours duration. Temperature and pressure varies from 338 to 738 K and 0 to 0.404 MPa, respectively. The material of construction is 1.25Cr-0.5Mo (SA-387 Gr. 11 Cl. 1). This coke drum is at higher temperature of 738 K for 24 hours in one full cycle. The skirt to shell and cone junction is a critical portion of coke drum because it is highly susceptible to fatigue at higher temperature. In addition to this, the skirt is provided with slots at specific pitch all around circumference to induce flexibility. This has great influence on fatigue life due to localized stress at higher temperature. API 579-1/ASME FFS-1 2007 is used for the fatigue life evaluation in the present case. Nonlinear transient thermal analysis is coupled with the elastic-plastic structural analysis for calculation of stresses and strains. These stresses are further used for deducing permissible cycles for fatigue as per the approach based on API 579-1. A Parametric study has been carried out in Finite Element Analysis tool ‘ANSYS-12.1’ for different configuration of skirt to cone junction specifically in terms of inside crotch radius. The effect on fatigue life has been studied with variation in inside crotch radius. It has been found that fatigue life at skirt to cone junction is increasing with increase in crotch radius. But, this increase in crotch radius is adversely effects on slot tip where the life is drastically reducing. Such parametric study can be considered for selection of inside crotch radius for given skirt thickness and diameter.

Creep-Fatigue Interaction in Coke Drums: An Approach Based on API 579-1/ASME FFS-1 2007

2009 ◽  
Author(s):  
M. Sohel M. Panwala ◽  
K. N. Srinivasan ◽  
S. L. Mehta
Keyword(s):  
Fatigue Damage ◽  
Theoretical Calculations ◽  
Variable Temperature ◽  
Great Influence ◽  
Creep Damage ◽  
Damage Factor ◽  
Part D ◽  
Creep Fatigue ◽  
Temperature And Pressure ◽  
Transient Thermal

Coke Drums are critical equipment in refineries due to variable temperature and pressure. The temperature is also very high and coke drums work in the creep range for some duration of one full cycle. The phenomenon of creep along with fatigue plays a very crucial role in failure of coke drums. In the present study, a coke drum is subjected to pressure–temperature reversal with each cycle of 48 hours duration. Temperature and pressure varies from 65 to 495 °C and 1.72 to 4.62 bar, respectively. The material of construction is 1.25Cr-0.5Mo. This material is in the creep range beyond 454 °C as defined by ASME Section II, Part D. This coke drum is in creep range for 23 hours of one full cycle. The skirt to shell and cone junction is a critical portion of coke drum because it is highly susceptible to creep and fatigue simultaneously. In addition to this, the skirt is provided with slots at specific pitch all around circumference to induce flexibility. This has great influence on creep and fatigue due to localized stress. API 579-1/ASME FFS-1 2007 is used for the creep fatigue interaction in the present case. Non-linear transient thermal analysis is coupled with the elastic-plastic structural analysis for calculation of stresses and strains. These stresses are further used in deducing a creep damage factor and strains are used for deducing permissible cycles for fatigue as per the approach based on API 579-1. A macro is developed in the commercially available Finite Element Code ANSYS 11 for calculation of the creep damage factor and permissible cycles for fatigue. The creep damage factor works out to be 0.01 and this has been used for deducing a fatigue damage factor from creep-fatigue interaction curve. The fatigue damage factor is found to be 0.9. The macro results are validated with theoretical calculations.

scholarly journals Prediction of Thermal Fatigue Life of Lead-Free BGA Solder Joints by Finite Element Analysis

2001 ◽  
Vol 42 (5) ◽  
pp. 809-813 ◽  
Author(s):  
Young-Eui Shin ◽  
Kyung-Woo Lee ◽  
Kyong-Ho Chang ◽  
Seung-Boo Jung ◽  
Jae Pil Jung
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Life ◽  
Thermal Fatigue ◽  
Solder Joints ◽  
Lead Free ◽  
Element Analysis ◽  
Thermal Fatigue Life

Fatigue Failure Behaviour Study of Automotive Lower Suspension Arm

2011 ◽  
Vol 462-463 ◽  
pp. 796-800 ◽  
Author(s):  
Nawar A. Kadhim ◽  
Shahrum Abdullah ◽  
Ahmad Kamal Ariffin ◽  
S.M. Beden
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Numerical Models ◽  
Good Alternative ◽  
Analysis Tool ◽  
Element Analysis ◽  
Finite Element Software ◽  
Life Model ◽  
Experimental Process ◽  
Behaviour Study

Fatigue life of automotive lower suspension arm has been studied under variable amplitude loadings. In simulation, the geometry of a sedan car lower suspension arm has been used. To obtain the material monotonic properties, tensile test has been carried out and to specify the material mechanical properties of the used material, a fatigue test under constant amplitude loading has been carried out using the ASTM standard specimens. Then, the results used in the finite element software to predict fatigue life has been evaluated later to show the accuracy and efficiency of the numerical models which they are appreciated. The finite element analysis tool is therefore proved to be a good alternative prior to the further experimental process. The predicted fatigue life from the simulation showed that Smith-Watson-Topper model provides longer life than Morrow and Coffin-Manson models. This is due to the different consideration for each strain-life model during life calculations.

Thermal-mechanical reliability analysis of WLP with fine-pitch copper post bumps

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Haiyan Sun ◽  
Bo Gao ◽  
Jicong Zhao
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Thermal Fatigue ◽  
Mechanical Performance ◽  
Three Dimension ◽  
Wafer Level ◽  
Element Analysis ◽  
Content Type ◽  
Cycle Simulation ◽  
Thermal Fatigue Life

Purpose This study aims to investigate the several parameters in wafer-level packaging (WLP) to find the most critical factor impacting the thermal fatigue life, such as the height of copper post, the height of solder bump, the thickness of chip. The FEA results indicate the height of solder bumps is the most important factor in the whole structure. Design/methodology/approach The copper post bumps with 65 µm pitch are proposed to investigate the thermal-mechanical performance of WLP. The thermal cycle simulation is used to evaluate the reliability of WLP by using finite element analysis (FEA). Taguchi method is adopted to obtain the sensitivity of parameters of three-dimension finite element model, for an optimized configuration. Findings It can be found that the optimal design has increased thermal fatigue life by 147% compared with the original one. Originality/value It is concluded that the finite element simulation results show outstanding thermal-mechanical performances of the proposed 65 µm pitch copper post bumps of WLP, including low plastic strain, high thermal fatigue life, which are desired for mobile device.

Finite element analysis on the thermal fatigue life of full vs peripheral array packages

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mohammad A. Gharaibeh
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Life ◽  
Thermal Cycling ◽  
Thermal Fatigue ◽  
Three Dimensional ◽  
Element Analysis ◽  
Content Type ◽  
Thermal Fatigue Life ◽  
Thermal Cycling Fatigue

PurposeThis paper aims to examine the thermal cycling fatigue life performance of two-common solder array configurations, full and peripheral, using three-dimensional nonlinear finite element analysis.Design/methodology/approachThe finite element simulations were used to identify the location of the critical solder interconnect, and using Darveaux's model, solder thermal fatigue life was computed.FindingsThe results showed that the solder array type does not significantly influence thermal fatigue life of the interconnect. However, smaller size packages result in improved life by almost 45% compared to larger package designs. Additionally, this paper provided an engineered study on the effect of the number of rows available in a perimeter array component on solder thermal fatigue performance.Originality/valueGeneral design recommendations for reliable electronic assemblies under thermal cycling loaded were offered in this research.

Thermal Fatigue Reliability of High-Temperature-Resistant Joint for Power Devices

2009 ◽  
Author(s):  
Hiromi Sugihara ◽  
Masanori Yamagiwa ◽  
Masato Fujita ◽  
Toshikazu Oshidari ◽  
Qiang Yu
Keyword(s):  
High Temperature ◽  
Thermal Fatigue ◽  
Critical Issue ◽  
Nano Particles ◽  
Fatigue Reliability ◽  
Analysis Model ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Higher Temperature ◽  
Micro Structures

The power electronics equipments for Electric vehicles such as the inverter are strongly demanded on downsizing and weight reduction. For these requirements, Silicon Carbide (SiC) devices are receiving particular attention. SiC devices are characterized by lower-loss and higher temperature operation compared with Si devices. Using the devices under high temperature, the cooling equipments can be miniaturized. However, a function of stress relaxation that the existing solder has is difficult to be expected in a high-temperature-resistant joint layer for SiC devices, because the joint layer is generally hard. So, the authors have proposed a new mounting structure that a metal circuit on a substrate has the function instead of the joint layer. In this study, high-temperature-resistant mounting structures that the chip was bonded by low temperature sintering method using Ag nano-particles to substrate with Ag/Ni plating are prepared. Thermal Cycle Test (TCT) using these samples of harsh temperature range was conducted. As a result a new critical issue on the chip joint was identified. To clarify the thermal fatigue mechanism, the Finite-Element-Analysis (FEA) was carried out. The analysis model simulated a thin layer of Ag/Ni plating and the high-temperature-resistant joint layer. By the FEM results, the thermal fatigue, particularly occurring crack, was affected by the micro structures.

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