STRUCTURAL DYNAMICS OF ELECTRONIC SYSTEMS

2013 ◽  
Vol 27 (07) ◽  
pp. 1330004 ◽  
Author(s):  
E. SUHIR

The published work on analytical ("mathematical") and computer-aided, primarily finite-element-analysis (FEA) based, predictive modeling of the dynamic response of electronic systems to shocks and vibrations is reviewed. While understanding the physics of and the ability to predict the response of an electronic structure to dynamic loading has been always of significant importance in military, avionic, aeronautic, automotive and maritime electronics, during the last decade this problem has become especially important also in commercial, and, particularly, in portable electronics in connection with accelerated testing of various surface mount technology (SMT) systems on the board level. The emphasis of the review is on the nonlinear shock-excited vibrations of flexible printed circuit boards (PCBs) experiencing shock loading applied to their support contours during drop tests. At the end of the review we provide, as a suitable and useful illustration, the exact solution to a highly nonlinear problem of the dynamic response of a "flexible-and-heavy" PCB to an impact load applied to its support contour during drop testing.

2010 ◽  
Vol 63 (5) ◽  
Author(s):  
E. Suhir

The published work on analytical (“mathematical”) and computer-aided, primarily finite-element-analysis based, predictive modeling of the dynamic response of electronic systems to shocks and vibrations is reviewed. Understanding the physics and the ability to predict the response of an electronic structure to dynamic loading has been always of significant importance in military, avionic, aeronautic, automotive, and maritime electronics. For the past decade, this problem has become important also in commercial, and, particularly, in portable, electronics in connection with accelerated testing on the board level of various surface-mount technology systems. The emphasis of this review is on the nonlinear behavior of flexible printed circuit boards experiencing shock loading applied to their support contours.


2009 ◽  
Vol 85 (6) ◽  
pp. 341-350 ◽  
Author(s):  
Jong-Bum Lee ◽  
Ja-Myeong Koo ◽  
Jong-Woong Kim ◽  
Bo-In Noh ◽  
Jong-Gun Lee ◽  
...  

2000 ◽  
Author(s):  
James F. Tarter

Abstract Finite element analysis has been used in conjunction with developed algorithms to analyze forced response and random vibration response of printed circuit boards. Analytical predictions have been compared to random vibration test data for model correlation and validation of the analysis methods. The described methods provide design data for predicting deflections and G levels as a function of frequency or predicting RMS levels for random excitation. These data are utilized for initiating design changes and guiding component placement. Deflection versus frequency contributions for random excitation are analyzed to identify critical design frequencies. Forced response contour plots include effects of modal coupling, modal participation factors, and system damping. These data provide a better description of the expected operating deflection shapes man a simple mode shape. All of these methods are used to improve design integrity and ensure specification compliance prior to hardware fabrication. The analyses utilize aggregate board properties, and do not currently provide data for individual components which are installed on the board.


Author(s):  
Salah Haridy ◽  
Zhang Wu ◽  
Amro Shafik

Computer numerical control (CNC) involves machines controlled by electronic systems designed to accept numerical data and other instructions, usually in a coded form. CNC machines are more productive than conventional equipment and consequently produce parts at less cost and higher accuracy even when the higher investment is considered. This article proposes an educational scheme for designing a CNC machine for drilling printed circuit boards (PCB) holes with small diameters. The machine consists of three-independently move-fully controlled tables. Output pulses from the personal computer (PC) parallel port are used to control the machine after processing by an interface card. A flexible, responsive and real-time visual C # program is developed to control the motion of the stepper motors. The educational scheme proposed in this article can provide engineers and students in academic institutions with a simple foundation to efficiently build a CNC machine based on the available resources.


Author(s):  
Jian Zhong ◽  
Ping Yang ◽  
Jian-ping Li ◽  
Hai-bo Sun ◽  
Quayle Chen ◽  
...  

The paper mainly presented mechanical test and failure analysis methods to reliability study of a new FPCB (Flexible Printed Circuit Boards). Mechanical tests include flexural test, tensile test and flexural fatigue and ductility test. As to simulation analysis, the stress distributions of FPCB under bending and tensile conditions were gained by simulations. Through in-depth analysis of the testing results, the mechanical reliability of FPCB was known detailed. The research provides an approach to improve FPCB performance.


2008 ◽  
Vol 47 (5) ◽  
pp. 4300-4304 ◽  
Author(s):  
Jong-Bum Lee ◽  
Ja-Myeong Koo ◽  
Soon-Min Hong ◽  
Hyoyoung Shin ◽  
Young-jun Moon ◽  
...  

2010 ◽  
Vol 163-167 ◽  
pp. 327-331 ◽  
Author(s):  
Liang Zheng ◽  
Zhi Hua Chen

Finite element model of both the single-layer Schwedler reticulated dome with the span of 50m and a Cuboid impactor were developed, incorporating ANSYS/LS-DYNA. PLASTIC_KINEMATIC (MAT_003) material model which takes stain rate into account was used to simulate steel under impact load. The automatic point to surface contact (NODES TO SURFACE) was applied between the dome and impact block. Three stages of time history curve of the impact force on the apex of the single-layer Scheduler reticulated dome including the impact stage, stable stalemate stage, the decaying stage were generalized according to its dynamic response. It must be pointed out that the peak of the impact force of the single-layer reticulated dome increase with the increase of the weight and the velocity of the impact block, but the change of the velocity of the impact block is more sensitive than the change of weight of the impact block for the effect of the peak of the impact force, and a platform value of the impact force of the single-layer reticulated dome change near a certain value, and the duration time of the impact gradually increase. Then four stages of time history curve of the impact displacement were proposed according to the dynamic response of impact on the apex of the single-layer reticulated dome based on numerical analysis. Four stages include in elastic deformation stage, plastic deformation stage, elastic rebound stage, free vibration stage in the position of the residual deformation.


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