Non-Perpendicular Orientation High-G Impact Reliability of Electronics Potted Assemblies

2020 ◽  
Author(s):  
Pradeep Lall ◽  
Aathi Raja Ram Pandurangan ◽  
Jeff Suhling ◽  
John Deep
Keyword(s):  
Solder Joint ◽  
Extreme Environments ◽  
Real Life ◽  
Element Model ◽  
Test Vehicle ◽  
Explicit Finite Element ◽  
Aerospace Applications ◽  
Test Assembly ◽  
Zero Degree ◽  
Impact Reliability

Abstract The Commercial electronics being used in defense and aerospace applications are being exposed to extreme environments including high-G shock conditions, which is not their intended purpose of use. Currently most of the board level testing is being done at horizontal zero degree drop angle. In real life drop scenarios, the angle of drop varies a lot. The damage accrued in the board interconnects and components and solder-joint interconnects, varies with the change in the drop angle. The reliability of the electronic components and interconnections of the solder-joint depends on the effect of drop angle on the test vehicle. The results acquired under these varying drop angle environments would be more relatable to the real life drop scenarios. The test vehicle is a circular PCB and two different configurations of the test vehicle are tested bare and potted. The boards are tested for three different drop angles of 0-degree, 30-degree and 60 degree. Two different shock levels are tested at each drop angle 10,000g and 25,000g. To predict the effect of drop angle on the test assembly, an explicit finite element model of the assembly has been created and simulated.

System Level Bench Test for Trailing Arm Strength Estimation

2006 ◽  
Author(s):  
Jaychandar Muthu ◽  
Kanak Soundrapandian ◽  
Jyoti Mukherjee
Keyword(s):  
Failure Mode ◽  
Real Life ◽  
Element Model ◽  
Suspension System ◽  
System Level ◽  
Bench Test ◽  
Component Level ◽  
Arm Strength ◽  
Bench Testing ◽  
Nonlinear Finite Element Model

For suspension components, bench testing for strength is mostly accomplished at component level. However, replicating loading and boundary conditions at the component level in order to simulate the suspension system environment may be difficult. Because of this, the component's bench test failure mode may not be similar to its real life failure mode in vehicle environment. A suspension system level bench test eliminates most of the discrepancies between simulated component level and real life vehicle level environments resulting in higher quality bench tests yielding realistic test results. Here, a suspension level bench test to estimate the strength of its trailing arm link is presented. A suspension system level nonlinear finite element model was built and analyzed using ABAQUS software. The strength loading was applied at the wheel end. The analysis results along with the hardware test correlations are presented. The reasons why a system level test is superior to a component level one are also highlighted.

Impact reliability estimation of lead free solder joint with IMC layer

2009 ◽  
Vol 517 (14) ◽  
pp. 4255-4259 ◽  
Author(s):  
Jong-Min Kim ◽  
Seung-Wan Woo ◽  
Yoon-Suk Chang ◽  
Young-Jin Kim ◽  
Jae-Boong Choi ◽  
...  
Keyword(s):  
Solder Joint ◽  
Reliability Estimation ◽  
Lead Free ◽  
Lead Free Solder ◽  
Free Solder ◽  
Impact Reliability

Finite Element Modeling of Unidirectional Non-Crimp Fabric for Manufacturing of Composites with Embedded Cabling

2013 ◽  
Vol 554-557 ◽  
pp. 484-491 ◽  
Author(s):  
Alexander S. Petrov ◽  
James A. Sherwood ◽  
Konstantine A. Fetfatsidis ◽  
Cynthia J. Mitchell
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Explicit Finite Element ◽  
Shell Elements ◽  
Beam Elements ◽  
Hybrid Finite Element ◽  
International Benchmarking ◽  
Unidirectional Glass ◽  
Forming Simulations

A hybrid finite element discrete mesoscopic approach is used to model the forming of composite parts using a unidirectional glass prepreg non-crimp fabric (NCF). The tensile behavior of the fabric is represented using 1-D beam elements, and the shearing behavior is captured using 2-D shell elements into an ABAQUS/Explicit finite element model via a user-defined material subroutine. The forming of a hemisphere is simulated using a finite element model of the fabric, and the results are compared to a thermostamped part as a demonstration of the capabilities of the used methodology. Forming simulations using a double-dome geometry, which has been used in an international benchmarking program, were then performed with the validated finite element model to explore the ability of the unidirectional fabric to accommodate the presence of interlaminate cabling.

The effects of well damage and completion designs on geo-electrical responses in mature wellbore environments

Geophysics ◽  
2021 ◽  
pp. 1-50
Author(s):  
Gungor D. Beskardes ◽  
Chester J. Weiss ◽  
Evan Um ◽  
Michael Wilt ◽  
Kris MacLennan
Keyword(s):  
Finite Element ◽  
Electrical Potential ◽  
Real Life ◽  
Element Model ◽  
Computational Effort ◽  
Real Surface ◽  
Well Completion ◽  
Geologic Storage ◽  
Well Damage ◽  
Electrical Responses

Well integrity is one of the major concerns in long-term geologic storage sites due to its potential risk for well leakage and groundwater contamination. Evaluating changes in electrical responses due to energized steel-cased wells has the potential to quantify and predict possible wellbore failures as any kind of breakage or corrosion along highly-conductive well casings will have an impact on the distribution of subsurface electrical potential. However, realistic wellbore-geoelectrical models that can fully capture fine scale details of well completion design and state of well damage at the field scale require extensive computational effort or can even be intractable to simulate. To overcome this computational burden while still keeping the model realistic, we utilize the Hierarchical Finite Element Method which represents electrical conductivity at each dimensional component (1-D edges, 2-D planes and 3-D cells) of a tetrahedra mesh. This allows us to consider well completion designs with real-life geometric scales and well systems with realistic, detailed, progressive corrosion and damage in our models. Here, we present a comparison of possible discretization approaches of a multi-casing completion design in the finite element model. The impacts of the surface casing length and the coupling between concentric well casings, as well as the effects of the degree and the location of well damage on the electrical responses are also examined. Finally, we analyze real surface electric field data to detect the wellbore integrity failure associated with damage.

Reinforced Solder Technology for Increased Reliability

2017 ◽  
Vol 2017 (1) ◽  
pp. 000641-000645
Author(s):  
Tim Jensen ◽  
Sunny Neoh ◽  
Adam Murling
Keyword(s):  
Melting Point ◽  
Solder Joint ◽  
Solder Joints ◽  
Reliability Of Solder Joints ◽  
Impact Reliability ◽  
Selection Of

Abstract The reliability of solder joints have been studied for many years. The selection of a solder for a particular application is often limited based on melting point requirements. This limits the number of options that are available for use. When alloy selection options are limited, people look to process changes to try and improve the reliability. Two such areas that have been identified that can impact reliability are bondline control and void reduction. This paper analyzes a new reinforced solder technology to maintain a consistent solder joint bondline. Experiments were also conducted to determine how best to design these preforms to minimize voiding.

Numerical and Experimental Investigation on the Energy Absorption Capability of a Full-Scale Composite Fuselage Section

2019 ◽  
Vol 827 ◽  
pp. 19-24 ◽  
Author(s):  
Donato Perfetto ◽  
Giuseppe Lamanna ◽  
M. Manzo ◽  
A. Chiariello ◽  
F. di Caprio ◽  
...  
Keyword(s):  
Finite Element ◽  
Energy Absorption ◽  
Load Condition ◽  
Element Model ◽  
Full Scale ◽  
Research Centre ◽  
Fe Method ◽  
Explicit Finite Element ◽  
Crashworthiness Design ◽  
The Impact

In the case of catastrophic events, such as an emergency landing, the fuselage structure is demanded to absorb most of the impact energy preserving, at the same time, a survivable space for the passengers. Moreover, the increasing trend of using composites in the aerospace field is pushing the investigation on the passive safety capabilities of such structures in order to get compliance with regulations and crashworthiness requirements. This paper deals with the development of a numerical model, based on the explicit finite element (FE) method, aimed to investigate the energy absorption capability of a full-scale 95% composite made fuselage section of a civil aircraft. A vertical drop test, performed at the Italian Aerospace Research Centre (CIRA), carried out from a height of 14 feet so to achieve a ground contact velocity of 30 feet/s in according to the FAR/CS 25, has been used to assess the prediction capabilities of the developed FE method, allowing verifying the response under dynamic load condition and the energy absorption capabilities of the designed structure. An established finite element model could be used to define the reliable crashworthiness design strategy to improve the survival chance of the passengers in events such as the investigated one.

Thermo-mechanical analysis of train wheel-rail contact using a novel finite-element model

2020 ◽  
Vol 72 (5) ◽  
pp. 687-693
Author(s):  
Liuqing Yang ◽  
Ming Hu ◽  
Deming Zhao ◽  
Jing Yang ◽  
Xun Zhou
Keyword(s):  
Finite Element ◽  
Peer Review ◽  
Frictional Heating ◽  
Element Model ◽  
Mechanical Analysis ◽  
Partial Slip ◽  
Computational Time ◽  
Fe Model ◽  
Content Type ◽  
Explicit Finite Element

Purpose The purpose of this paper is to develop a novel method for analyzing wheel-rail (W-R) contact using thermo-mechanical measurements and study the effects of heating on the characteristics of W-R contact under different creepages. Design/methodology/approach This study developed an implicit-explicit finite element (FE) model which could solve both partial slip and full sliding problems by setting different angular velocities on the wheels. Based on the model, four material types under six different creepages were simulated. Findings The results showed that frictional heating significantly affected the residual stress distribution under large creepage conditions. As creepage increased, the temperature of the wheel tread and rail head rose and the peak value was located at the trailing edge of the contact patch. Originality/value The proposed FE model could reduce computational time and thus cost to about one-third of the amount commonly found in previous literature. Compared to other studies, these results are in good agreement and offer a reasonable alternative method for analyzing W-R contact under various conditions. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2019-0298

Damage Mechanisms in Polymer Matrix Composites in Extreme Environments

2006 ◽  
Vol 324-325 ◽  
pp. 663-666 ◽  
Author(s):  
Maciej S. Kumosa
Keyword(s):  
High Temperature ◽  
Polymer Matrix ◽  
High Voltage ◽  
Polymer Matrix Composites ◽  
Rocket Engine ◽  
Extreme Environments ◽  
Combined Cycle ◽  
Matrix Composites ◽  
Aerospace Applications ◽  
Liquid Propellant Rocket Engine

In this work, potential problems with the application of polymer matrix composites (PMC) in extreme environments [1] is discussed. Then, two specific examples of the applications of PMCs in high voltage [2-7] and high temperature [8-15] situations are evaluated. The first example deals with damage evolution in high voltage composite insulators [2-7] with PMC rods subjected to a combined action of extreme mechanical, electrical and environmental stresses. These insulators are widely used in transmission line and substation applications around the world. Subsequently, advanced high temperature graphite/polyimide composites [8-15] are evaluated for aerospace applications. The composite investigated in this project were used to manufacture and successfully test a Rocket Based Combined Cycle (RBCC) third-generation, reusable liquid propellant rocket engine, which is one possible engine for a future single-stage-to-orbit vehicle [8].

Virtual Testing for Frontal Impact of High-Top Cab of Heavy Truck

2011 ◽  
Vol 148-149 ◽  
pp. 1081-1084
Author(s):  
Wei Wang ◽  
Xu Liang Xie ◽  
Fu Lin Shen ◽  
Xiao Feng Wang
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Front Seat ◽  
Finite Element Program ◽  
Explicit Finite Element ◽  
Commercial Code ◽  
Element Program ◽  
Heavy Truck ◽  
Survival Space ◽  
Pendulum Impact

ECE R29 regulation has legally claimed that the survival space must be guaranteed for the safety for driver and front seat passenger in event of crash during design of truck cabin. In this paper, a finite element model of a high-top cabin of a heavy truck with a manikin on the driver seat was built with commercial code Hypermesh, The explicit finite element program Ls-Dyna was used to simulate the frontal pendulum impact on the high-top cab in the light of ECE R29 regulation. Deformation of the truck cabin and the survival space of the dummy were analyzed and discussed. Also, some suggestions were given to solve the contact possibility between steering column and the knees of manikin.

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