Determining failure modes devoid of redundant elements for pin-bar structures using null space of equilibrium matrix

In this paper, the failure of parallel manipulators is investigated. Failure modes of parallel manipulators and their causes and effects from the kinematics point of view are discussed. Methodologies for investigating the effect of failures, due to joint failure or singularity, on the motion performance of manipulators are presented, and the criteria for full and partial recovery from these failures are established. The proposed methodologies are based on the projection of the lost motion onto the orthogonal complement of the null space of the Jacobian matrix after failure. The procedure is simulated for planar parallel manipulators to examine if after joint failure the required motion of manipulator could be fully recovered; as well as to calculate the corrections to the motion of remaining joints for recovering the lost motion.

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Scanning Electron Microscopy in Hybrid Microelectronics

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100092244 ◽

1976 ◽

Vol 34 ◽

pp. 456-457

Author(s):

S. Khadpe ◽

R. Faryniak

Keyword(s):

Integrated Circuits ◽

Thick Film ◽

Integrated Circuit ◽

Failure Modes ◽

Three Dimensional ◽

Circuit Components ◽

Hybrid Microcircuit ◽

Electrical Connections ◽

Scanning Electron

The Scanning Electron Microscope (SEM) is an important tool in Thick Film Hybrid Microcircuits Manufacturing because of its large depth of focus and three dimensional capability. This paper discusses some of the important areas in which the SEM is used to monitor process control and component failure modes during the various stages of manufacture of a typical hybrid microcircuit.Figure 1 shows a thick film hybrid microcircuit used in a Motorola Paging Receiver. The circuit consists of thick film resistors and conductors screened and fired on a ceramic (aluminum oxide) substrate. Two integrated circuit dice are bonded to the conductors by means of conductive epoxy and electrical connections from each integrated circuit to the substrate are made by ultrasonically bonding 1 mil aluminum wires from the die pads to appropriate conductor pads on the substrate. In addition to the integrated circuits and the resistors, the circuit includes seven chip capacitors soldered onto the substrate. Some of the important considerations involved in the selection and reliability aspects of the hybrid circuit components are: (a) the quality of the substrate; (b) the surface structure of the thick film conductors; (c) the metallization characteristics of the integrated circuit; and (d) the quality of the wire bond interconnections.

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Sulfate Attack Induced Dry–Wet Failure Modes and a Constitutive Model for Mortar Specimens with a Single Intermittent Fracture

International Journal of Geomechanics ◽

10.1061/(asce)gm.1943-5622.0001909 ◽

2021 ◽

Vol 21 (2) ◽

pp. 04020249

Author(s):

Tielin Han ◽

Zhihui Li ◽

Yunsheng Chen

Keyword(s):

Constitutive Model ◽

Failure Modes ◽

Sulfate Attack

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Profit Analysis of a Two Similar Unit Cold Standby Redundant System with Different Failure Modes with Expert Repairman

International Journal of Scientific Research ◽

10.15373/22778179/july2013/86 ◽

2012 ◽

Vol 2 (7) ◽

pp. 266-267

Author(s):

Dr. Vijay Kumar Dr. Vijay Kumar ◽

◽

Dr. Nitin Bhardwaj Dr. Nitin Bhardwaj

Keyword(s):

Failure Modes ◽

Redundant System ◽

Profit Analysis ◽

Cold Standby ◽

Similar Unit

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Human reliability in non-destructive inspections of nuclear power plant components: modeling and analysis

Brazilian Journal of Radiation Sciences ◽

10.15392/bjrs.v7i2b.368 ◽

2019 ◽

Vol 7 (2B) ◽

Author(s):

Vanderley Vasconcelos ◽

Wellington Antonio Soares ◽

Raissa Oliveira Marques ◽

Silvério Ferreira Silva Jr ◽

Amanda Laureano Raso

Keyword(s):

Power Plant ◽

Nuclear Power Plant ◽

Human Factors ◽

Nuclear Power ◽

Power Plants ◽

Failure Modes ◽

Cooling System ◽

Human Reliability ◽

Non Destructive ◽

Plant Components

Non-destructive inspection (NDI) is one of the key elements in ensuring quality of engineering systems and their safe use. This inspection is a very complex task, during which the inspectors have to rely on their sensory, perceptual, cognitive, and motor skills. It requires high vigilance once it is often carried out on large components, over a long period of time, and in hostile environments and restriction of workplace. A successful NDI requires careful planning, choice of appropriate NDI methods and inspection procedures, as well as qualified and trained inspection personnel. A failure of NDI to detect critical defects in safety-related components of nuclear power plants, for instance, may lead to catastrophic consequences for workers, public and environment. Therefore, ensuring that NDI is reliable and capable of detecting all critical defects is of utmost importance. Despite increased use of automation in NDI, human inspectors, and thus human factors, still play an important role in NDI reliability. Human reliability is the probability of humans conducting specific tasks with satisfactory performance. Many techniques are suitable for modeling and analyzing human reliability in NDI of nuclear power plant components, such as FMEA (Failure Modes and Effects Analysis) and THERP (Technique for Human Error Rate Prediction). An example by using qualitative and quantitative assessesments with these two techniques to improve typical NDI of pipe segments of a core cooling system of a nuclear power plant, through acting on human factors issues, is presented.

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Corrosion of Electronic and Magnetic Devices and Materials

MRS Proceedings ◽

10.1557/proc-451-541 ◽

1996 ◽

Vol 451 ◽

Author(s):

Gerald S. Frankel

Keyword(s):

Thin Film ◽

Failure Modes ◽

Galvanic Corrosion ◽

Potential Drop ◽

Magnetic Devices ◽

Disk Structure ◽

Magnetic Layers ◽

Ohmic Potential Drop ◽

Corrosion Problem ◽

Corrosion Susceptibility

ABSTRACTCorrosion of thin film structures commonly used in electronic and magnetic devices is discussed. Typical failure modes are presented, and galvanic corrosion is discussed in some detail since it is one common problem with such devices. A graphical explanation for the determination of the ohmic potential drop during galvanic corrosion is presented. The corrosion problem of thin film disks is shown to have changed during the past ten years owing to changes in disk structure. The corrosion susceptibility of two antiferromagnetic alloys used for exchange coupling to soft magnetic layers is discussed.

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