Survey of Design and Process Failure Modes for High-Speed SerDes in Nanometer CMOS

2005 ◽  
Author(s):  
C. Dryden
Keyword(s):  
High Speed ◽  
Failure Modes ◽  
Nanometer Cmos ◽  
Process Failure

Reverse Fishbone Diagram: A Tool in Aid of Design for Product Retirement

1996 ◽  
Author(s):  
Kosuke Ishii ◽  
Burton H. Lee
Keyword(s):  
Failure Modes ◽  
Graphical Representation ◽  
Environmentally Conscious ◽  
The Past ◽  
Advanced Planning ◽  
Process Failure ◽  
Fishbone Diagram ◽  
Useful Life ◽  
Definition Of ◽  
Central Tool

Abstract This paper describes a schematic representation of product retirement specification that aids in design for recycling and reuse. In the past decade, a graphical representation of the assembly process, called the assembly fishbone diagram, has effectively assisted engineers to conduct design for assembly (DFA) and process failure modes and effects analysis (FMEA). On the other hand, environmentally conscious manufacturing requires engineers to make advanced planning for product retirement. This study investigates the use of the reverse fishbone diagram to model the disassembly and reprocessing sequence of a product at the end of its useful life. An industry-provided student project guided us to an initial definition of the reverse fishbone diagram that effectively led the students to analyze the recyclability and make practical redesign suggestions. The diagram is continuously adding more rigorous definitions and promises to be a central tool for evaluation of recyclability in a simultaneous engineering setting.

C-section Cold-Formed Steel as Structural Members in Housing Construction in the Philippines

2019 ◽  
Author(s):  
Bernardo A. Lejano
Keyword(s):  
Axial Compression ◽  
High Speed ◽  
Failure Modes ◽  
Weight Ratio ◽  
High Strength ◽  
The Philippines ◽  
Bending Test ◽  
Housing Construction ◽  
Distortional Buckling ◽  
Cold Formed Steel

<p>Getting good lumber for housing construction is becoming difficult in the Philippines due to existing partial log ban. Although, the use of reinforced concrete is still the most popular in construction, an emerging alternative is the use of cold-formed steel (CFS). It is gaining popularity because of its high strength-to- weight ratio. However, information about the structural performance of locally-produced cold-formed steel is almost nonexistent. Although, design provisions are stipulated in the local Code, these are based on formulas developed abroad, hence the need to investigate these cold-formed steel. This study focuses on the C-section cold-formed steel, which is the most popularly used. The objective is to verify its performance when subjected to axial compression and flexure, both experimentally and computationally. For the computational part, the formulas stipulated in the National Structural Code of the Philippines were followed. For the experimental part, the cold-formed steel members were subjected to compression loads and flexural loads. Aside from usual sensors, high-speed cameras were used to capture the failure modes. For axial compression test, 80 specimens with different lengths and thicknesses were tested. For flexure, 24 specimens of back-to-back C-sections were subjected to 4-point bending test. Results showed the predicted strengths were well below the experimental values. In design, this means the use of Code-based formulas is conservative. Failure modes observed were torsional buckling and distortional buckling. Comparison of failure modes between experiment and computation shows 70% agreement for compression and 75% for flexure. Finite element method calculations were also done and were compared with experimental results.</p>

A Methodology for High Cycle Fatigue Characterization of Lead-Free Interconnects Under Simultaneous Harsh Environments of High Temperature and Vibration

2013 ◽  
Author(s):  
Pradeep Lall ◽  
Geeta Limaye
Keyword(s):  
High Temperature ◽  
High Speed ◽  
High Cycle Fatigue ◽  
Failure Modes ◽  
Elevated Temperatures ◽  
Natural Frequencies ◽  
Image Correlation ◽  
Lead Free ◽  
Cycle Fatigue ◽  
Increase With Increase

Current trends in the automotive industry warrant a variety of electronics for improved control, safety, efficiency and entertainment. Many of these electronic systems like engine control units, variable valve sensor, crankshaft-camshaft sensors are located under-hood. Electronics installed in under-hood applications are subjected simultaneously to mechanical vibrations and thermal loads. Typical failure modes caused by vibration induced high cycle fatigue include solder fatigue, copper trace or lead fracture. The solder interconnects accrue damage much faster when vibrated at elevated temperatures. Industry migration to lead-free solders has resulted in a proliferation of a wide variety of solder alloy compositions. Presently, the literature on mechanical behavior of lead-free alloys under simultaneous harsh environment of high-temperature vibration is sparse. In this paper, the reduction in stiffness of the PCB with temperature has been demonstrated by measuring the shift in natural frequencies. The test vehicle consisting of a variety of lead-free SAC305 daisy chain components including BGA, QFP, SOP and TSOPs has been tested to failure by subjecting it to two elevated temperatures and harmonic vibrations at the corresponding first natural frequency. The test matrix includes three test temperatures of 25C, 75C and 125C and simple harmonic vibration amplitude of 10G which are values typical in automotive testing. PCB deflection has been shown to increase with increase in temperature. The full field strain has been extracted using high speed cameras operating at 100,000 fps in conjunction with digital image correlation. Material properties of the PCB at test temperatures have been measured using tensile tests and dynamic mechanical analysis. FE simulation using global-local finite element models is thus correlated with the system characteristics such as modal shapes, natural frequencies and displacement amplitudes for every temperature. The solder level stresses have been extracted from the sub-models. Stress amplitude versus cycles to failure curves are obtained at all the three test temperatures. A comparison of failure modes for different surface mount packages at elevated test temperatures and vibration has been presented in this study.

Thermal–Hydraulic Performance Analysis for AP1000 Passive Containment Cooling System

2013 ◽  
Author(s):  
Yu Yu ◽  
Shengfei Wang ◽  
Fenglei Niu
Keyword(s):  
System Reliability ◽  
Nuclear Power ◽  
Failure Modes ◽  
Cooling System ◽  
Natural Circulation ◽  
Hydraulic Performance ◽  
Reactor Power ◽  
Physical Parameters ◽  
Cold Source ◽  
Process Failure

In order to improve the safety of new generation nuclear power plant, passive containment cooling system is innovatively used in AP1000 reactor design. However, since the system operation is based on natural circulation, physical process failure — natural circulation cannot establish or be maintained — becomes one of the important failure modes. Uncertainties in the physical parameters such as heat and cold source temperature and in the structure parameters have important effect on the system reliability. In this paper, thermal–hydraulic model is established for passive containment cooling system in AP1000 and the thermal–hydraulic performance is studied, the effect of factors such as air temperature and reactor power on the system reliability are analyzed.

Design, Simulation and Testing of Overpack Encapsulation Vessels

2012 ◽  
Author(s):  
A. Towse ◽  
J. Dodds
Keyword(s):  
Pressure Vessel ◽  
High Speed ◽  
Failure Modes ◽  
Inner Product ◽  
Central Position ◽  
Video Footage ◽  
Rule Approach ◽  
The Moment ◽  
Explicit Dynamic ◽  
The Impact

The paper presents an overpack designed to contain nuclear product cans which may become pressurised or contaminated. The overpack provides a protective barrier to an inner product can, and due to the possibility of leakage of gas from the contents, the overpack must also function as a pressure vessel. Furthermore, the overpack is required to provide physical protection to the inner can and proof of containment was therefore necessary under a number of different impact scenarios, both pre-pressurised and also with the simulation of pressurisation at the moment of impact. Additionally, the inner product can was to be maintained in a central position during the deceleration at impact. This paper focuses on the analytical design and substantiation of the impact of the system which was performed using an explicit dynamic solver for a number of impact orientations. The design of the overpack to satisfy the relevant pressure vessel Code are not discussed in detail. The potential failure modes of the overpack during impact were assessed and design improvements made over a number of iterations. Following completion of the design and simulation phase, prototypes were built and tested to verify the engineering design and analysis. The testing showed that simulation driven design in conjunction with a pressure vessel design by rule approach was successful in creating a solution for the product can encapsulation. A comparison between the analytical simulation and high-speed video footage of the testing was also made.

Challenges and Methods in the Quantification of Design Errors and Solution Elements

2004 ◽  
Author(s):  
Lawrence P. Chao ◽  
Kosuke Ishii
Keyword(s):  
Design Process ◽  
Life Cycle Cost ◽  
Quality Function Deployment ◽  
Failure Modes ◽  
Spatial Distance ◽  
Risk Priority Number ◽  
Design Elements ◽  
Process Failure ◽  
Temporal And Spatial ◽  
Process Level

To error-proof the design process, tools such as Design Process Failure Modes and Effects Analysis and Project Quality Function Deployment mitigate risk through thorough understanding of the consequences of both the process-level errors that can occur and the solution elements that mitigate them. However, the quantification of design errors and prioritization of other elements are complicated by the temporal and spatial distance of the decisions from the end-result. This paper discusses measures for design elements in the context of process-based analysis, including the design errors, tasks, and project resources. The Risk Priority Number is the standard measure of criticality of failure modes and their effects. However, alternatives to the traditional RPN have emerged in forms such as expected and life-cycle cost as well as QFD-based techniques. The paper explores the benefits and challenges of these traditional and new measures and concludes with a discussion into converting between the measures.

Laboratory and Field Investigation of the Rail Pad Assembly Mechanistic Behavior

2014 ◽  
Author(s):  
Thiago B. do Carmo ◽  
J. Riley Edwards ◽  
Ryan G. Kernes ◽  
Bassem O. Andrawes ◽  
Chris P. L. Barkan
Keyword(s):  
High Speed ◽  
Failure Modes ◽  
Lateral Displacement ◽  
Relative Displacement ◽  
Field Investigation ◽  
High Speed Rail ◽  
Component Design ◽  
Scientific Principles ◽  
Heavy Haul ◽  
And Performance

To achieve the performance demands due to growing heavy-haul freight operations and increased high-speed rail service worldwide, advancements in concrete crosstie fastening systems are required. A mechanistic design approach based on scientific principles and derived from extensive laboratory and field investigation has the potential to improve the current best practices in fastening system design. The understanding of failure modes and effects on each component, associated with an improved understanding of load distribution and mechanical behavior, will ultimately increase production and operational efficiency while reducing unscheduled maintenance, track outages, and unplanned additional costs. Improvements on the rail pad assemblies, the components responsible for attenuating loads and protecting the concrete crosstie rail seat, will enhance the safety and efficiency of the track infrastructure. Understanding the mechanistic behavior of rail pad assemblies is critical to improving the performance and life cycle of the infrastructure and its components, which will ultimately reduce the occurrence of potential failure modes. Lateral, longitudinal, and shear forces exerted on the components of the fastening system may result in displacements and deformations of the rail pad with respect to the rail seat and rail base. The high stresses and relative movements are expected to contribute to multiple failure mechanisms and result in an increased need for costly maintenance activities. Therefore, the analysis of the mechanics of pad assemblies is important for the improvement of railroad superstructure component design and performance. In this study, the lateral displacement of this component with respect to the rail base and rail seat is analyzed. The research ultimately aims to investigate the hypothesis that relative displacement between the rail pad and rail seat occurs under realistic loading environments and that the magnitude of the displacement is directly related to the increase in wheel loads.

Optimizing Electrical Protection for Medium Voltage Controller Lineup to Improve Liquids Pipelines Operation Reliability and Safety

2018 ◽  
Author(s):  
Ting Yu ◽  
Tushar Chaitanya
Keyword(s):  
Proximity Effect ◽  
Incident Energy ◽  
High Speed ◽  
Large Scale ◽  
Failure Modes ◽  
Partial Discharge ◽  
Light Detection ◽  
Medium Voltage ◽  
Voltage Controller ◽  
The Impact

MV (Medium Voltage) controller lineup electrical protection is crucial in protecting the equipment from large scale damage upon the occurrence of an electrical fault, reducing the time to restore power, thereby minimizing the impact to liquids pipelines operation. The paper discusses typical electrical failure modes that may occur in MV controller lineups, and demonstrates practical relaying engineering techniques that enable fast and effective fault clearing. Electrical faults in the MV controller lineup are often arcing type, commonly involve ground. Mitigating arc hazards in MV Class E2 controller lineups has traditionally been challenging without sacrificing the protection selectivity. As the paper demonstrates, a relaying scheme with the combined use of high-speed light-sensing and overcurrent detection will effectively mitigate the incident energy, while maintaining the protection selectivity for non-arcing overcurrent events. For new MV controller lineups, in addition to the “high-speed light detection and fault interruption”, zone-selective interlocking (ZSI) can also be a practical solution in improving relay protection speed, thus reduce the chance of severe arc flash occurrences. ZSI is particularly effective for fault occurrences on the line side of the phase CTs, busways or main incoming circuits. The ZSI scheme can be implemented on both Class E2 and circuit breaker (VCB) type MV controller lineups, however, with slightly different trip logic due to the limited fault clearing capability of the contactor. Although there are multiple contributing factors, the direct causes of electrical failures in MV controller lineup are commonly related to improper power cable installation and handling, potentially leading to premature insulation breakdown due mainly to the proximity effect and/or partial discharge. Inadequate cable separation and prolonged fault trip delay can increase the possibility of arcing fault occurrence. This can usually be mitigated through appropriate cable spacing, adequate conductor insulation, and optimized fault detection schemes. The paper provides overviews of the mechanisms of proximity effect and partial discharge propagation, and the modern relaying approaches for accurate fault type discrimination and facilitating fast fault interruption. Two case studies are provided in the paper as an aid in understanding the electrical fault mechanism originated from cable insulation failure, demonstrating the incident energy reduction before and after the implementation of high-speed light detection and fault interruption solutions on an existing MV controller lineup.

scholarly journals Experimental Study on the Skidding Damage of a Cylindrical Roller Bearing

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4075 ◽  
Author(s):  
Qing Zhang ◽  
Jun Luo ◽  
Xiang-yu Xie ◽  
Jin Xu ◽  
Zhen-huan Ye
Keyword(s):  
High Speed ◽  
Large Scale ◽  
Failure Modes ◽  
Roller Bearing ◽  
Weight Ratio ◽  
Operating Conditions ◽  
Roller Bearings ◽  
Light Load ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

As large-scale rotating machines develop toward high rotating speed and high power–weight ratio, skidding damage has become one of the major initial failure modes of cylindrical roller bearings. Therefore, understanding the skidding damage law is an effective way to ensure the safety of machines supported by cylindrical roller bearings. To realize the skidding damage, a high-speed rolling bearing test rig that can simulate the actual operating conditions of aviation bearings was used in this paper, and the skidding damage dynamic behaviors of cylindrical roller bearings were investigated. In addition, to ensure the accuracy of the obtained skidding damage mechanism, the cylindrical roller bearing was carefully inspected by microscopic analysis when the skidding damage occurred. Out results show that instantaneous increases in friction torque, vibration acceleration, and temperature are clearly observed when the skidding damage occurs in the cylindrical roller bearing. Furthermore, under the conditions of inadequate lubrication and light load, the critical speed of skidding damage is rather low. The major wear mechanisms of skidding damage include oxidation wear, abrasive wear, and delamination wear. The white layers are found locally in the inner ring and rollers under the actions of friction heat and shear force.

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