Boundary Element Analysis for Piezoelectric Cracks by an Interaction Integral

2015 ◽  
Vol 1120-1121 ◽  
pp. 1390-1394
Author(s):  
He Guo Liu ◽  
Jun Lei ◽  
Peng Bo Sun ◽  
Qing Sheng Yang
Keyword(s):  
Crack Problem ◽  
Crack Tip Field ◽  
Element Analysis ◽  
Interaction Integral ◽  
Center Crack ◽  
Field Intensity Factors ◽  
Boundary Element Analysis ◽  
Independent Behavior ◽  
Edge Crack Problem ◽  
Good Agreement

In this paper, an interaction integral is applied to evaluate the crack-tip field intensity factors for piezoelectric cracks by using BEM. Based on this, the fracture parameters for different crack configurations and loading conditions are analyzed in details for both the center crack and edge crack problem. According to the present results, the path-independent behavior of the interaction integral is verified. The comparison of the I-integral results with those by the J-integral and the displacement interpolating methods shows a good agreement.

scholarly journals Predicting Silicon Die Breaking Force in Semiconductor Package Assembly through Mechanical Simulation

2021 ◽  
pp. 17-25
Author(s):  
Jefferson Talledo
Keyword(s):  
Loading Condition ◽  
Semiconductor Industry ◽  
Crack Problem ◽  
Cost Effective ◽  
Maximum Principal Stress ◽  
Assembly Process ◽  
Breaking Force ◽  
Element Analysis ◽  
Mechanical Simulation ◽  
Good Agreement

Die crack is a common problem in the semiconductor industry and being able to predict the breaking force at a given loading condition could help prevent such crack problem. This paper presents the use of mechanical simulation in predicting the force at which the silicon die breaks in semiconductor package assembly process. A computer simulation with finite element analysis (FEA) technique was used. The applied force or displacement in a die bending simulation with 3 mm, 4 mm and 15 mm support span was varied until the resulting maximum principal stress of the die becomes equal to its fracture strength. Results revealed that the breaking force for the 70 µm die with 6 mm width is around 5 N for the 3 mm support span and only around 1 N for the 15 mm support span. With the good agreement between modeling and actual results, the study showed that mechanical simulation is an effective approach in predicting die breaking force and can be used to simulate different mechanical loads in the package assembly where possible die crack could happen and be avoided. This is a fast and cost-effective way of assessing risk of die crack and obtaining package assembly process parameters and specifications that are safe to the silicon die.

Computer Modeling of a Tire under Cornering Loads

1989 ◽  
Vol 17 (2) ◽  
pp. 86-99 ◽  
Author(s):  
I. Gardner ◽  
M. Theves
Keyword(s):  
Finite Element Analysis ◽  
Geometric Approach ◽  
Lateral Force ◽  
Slip Angle ◽  
Element Analysis ◽  
Pressure Distributions ◽  
Slip Effects ◽  
Improved Accuracy ◽  
Nonlinear Geometric ◽  
Good Agreement

Abstract During a cornering maneuver by a vehicle, high forces are exerted on the tire's footprint and in the contact zone between the tire and the rim. To optimize the design of these components, a method is presented whereby the forces at the tire-rim interface and between the tire and roadway may be predicted using finite element analysis. The cornering tire is modeled quasi-statically using a nonlinear geometric approach, with a lateral force and a slip angle applied to the spindle of the wheel to simulate the cornering loads. These values were obtained experimentally from a force and moment machine. This procedure avoids the need for a costly dynamic analysis. Good agreement was obtained with experimental results for self-aligning torque, giving confidence in the results obtained in the tire footprint and at the rim. The model allows prediction of the geometry and of the pressure distributions in the footprint, since friction and slip effects in this area were considered. The model lends itself to further refinement for improved accuracy and additional applications.

Numerical Calculation of Aerodynamic Noise for the Nose Cone Surface in High Speed Airflow Field

2014 ◽  
Vol 488-489 ◽  
pp. 886-891
Author(s):  
Ai Jian Zheng ◽  
Feng Niu ◽  
Hai Jiang Zhu
Keyword(s):  
Numerical Calculation ◽  
High Speed ◽  
Aerodynamic Noise ◽  
Element Analysis ◽  
Analysis Theory ◽  
Nose Cone ◽  
Flow Induced Noise ◽  
Airflow Field ◽  
Boundary Element Analysis ◽  
Acoustic Boundary Element

This paper presents two nose cones models and their numerical calculation of aerodynamic noise in high speed airflow field combining the analysis theory of fluid dynamics with the acoustic boundary element analysis method. The noise sound pressure levels (SPL) of these two models are calculated under the different speed airflow. And we compare the SPL of the better model with that of commercial nose cone models. These simulated results show that the aerodynamic noise of the nose cone with a ellipsoid head has lower flow-induced noise than that of commercial nose cone models at relative high air flow velocities at most frequencies.

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