Product Malfunctions Research Articles

Forensic materials and test methods

In recent years, forensic engineering, a growing field of engineering, has developed. If the product malfunctions prematurely, the user will not be able to use that product, and sometimes it may lead to personal injuries. Sophisticated techniques such as SEM and DSC are used to study these problems. Forensic engineers evaluate documentary evidence so that the court can make the right decision. In this study, forensic materials and test methods are discussed. For this purpose, first, the concept of Forensic Engineering was introduced and the defects occurring in the products were examined. Then, in case of a dispute between the parties, it is explained how forensic engineers examine the products and prepare an expert report to resolve the dispute. Finally, how and with which devices macroscopic and microscopic tests, mechanical and thermal tests were performed were examined.

Aspect-based Sentiment Analysis on Electric Motorcycles: Users’ Perspective

Electric Vehicles (EVs) adoption is emerging especially electric motorcycles due to their lower price. Research has shown that the majority of people have positive sentiments towards EVs but most of the sentiments were from people who did not already own or use EVs, but rather from people who reacted / commented towards a product that is recently being launched/announced. This research aims to evaluate users’ opinions regarding the positive and negative aspects of electric motorcycles they had purchased / used. This information will be beneficial for the manufacturers and marketers as an evaluation for their products; and it is also beneficial for prospective buyers as a buying consideration. This research uses Aspect-Based Sentiment Analysis applied on 844 electric motorcycles review data from www.bikewale.com website. Results showed that the notable positive sentiments are related to smooth riding experience and low maintenance. Whereas notable negative sentiments are related to poor build quality and product malfunctions. The other aspects of electric motorcycles received mixed sentiments such as related to vehicle speed and customer service. The research findings, limitations, and future research direction are discussed.

SYSTEMATIC LITERATURE REVIEW ON THE APPLICATION OF ADDITIVE MANUFACTURING IN REPAIR AND RESTORATION

The process of repair and restoration is crucial to environmental sustainability as it allows parts or products to be reinstated like a new condition before moving on to the next stage of their life cycles. Presently, skilled workers manually do these tasks. With the introduction of additive manufacturing (AM), people are exploring its possibilities for automated repair and restoration, making it a more efficient technique for remanufacturing. This systematic review aims to identify the application of AM specifically in repair and restoration. The search was carried out using all accessible electronic databases. 75 articles were found that fulfilled the search criteria. The gap in each article was discovered, to provide comprehensive coverage of repairing techniques of parts made of the same or different materials. The findings show that AM technology heralds a new era of repairability. Using AM for repair and restoration shows promising results, motivating more research. In addition, AM shows transformational potential for creating, making, distributing, and repairing goods. Printing replacement components is an example of a step toward this transition. AM provides a rapid and effective repair solution when product malfunctions and specific replacement components are unavailable or limited.

Inaction Traps in Consumer Response to Product Malfunctions

The authors develop and test a theory of consumer inaction traps in the domain of decisions to either address or endure product malfunctions. According to this theory, the magnitude of product malfunctions can have a paradoxical effect on consumption experience. In particular, the less severe a product malfunction is, the more inclined consumers are to defer the initial decision about whether to take corrective action. Subsequent opportunities for corrective action are devalued relative to previously forgone ones. This dynamic tends to trap consumers in a state of inaction, resulting in their enduring smaller malfunctions longer than larger ones. A consequence of these inaction traps is that minor product malfunctions may result in less enjoyable overall consumption experiences than more severe defects. Evidence from eight experiments and a survey provides support for this theorizing by demonstrating the inaction-trap phenomenon, examining its downstream consequences, shedding light on the psychological dynamics of inaction, and identifying boundary conditions that suggest interventions for counteracting consumers’ vulnerability to suffering disproportionately from relatively minor product malfunctions.

Paradigm of Safety by Design

Safety by design is a challenge not because designers are unwilling to design safe products or systems but because they focus on the creation of products that fulfil customer wishes as much as possible, and it is hard to focus on intended functions for a product and unintended functions or malfunctions at the same time. The paper highlights the ever-increasing safety challenges for designers, and it argues that safety must be an integral part of the design process.

Prediction of die-roll in fine blanking by use of profile parameters

Abstract Fine blanking (FB) is a press shearing process that can obtain a smooth clean-cut sheared edge surface in one press stroke. However, the convex portion of the punched out part or product will generally include a large amount of die-roll or shear-droop defined by a component (Z) in the shear plane direction (z-direction) as well as in the planar direction (x-direction). The droop often will cause various product malfunctions, such as decrease in the contact length as in the engagement of a gear pair by the larger z-directional droop, and a reduction of the effective contact area with the x-directional droop. Since the FB process inevitably causes droop, leading to the reduced functionality of parts, the amount of droop is an important factor, when fabricating parts, using the FB method. Therefore, our final aim is to realize fine-blanked components without droop. As the first step, we attempted to predict the dependence of the amount of droop on the FB parameters which include the punch-die clearance, the material and its thickness, the included angle, and the radius of the convex portion in the case of common work piece profile components. From careful observation of the experimental results for various work materials and that were fine-blanked by an FB die set, we were able to obtain a simple and integrated formula to predict the amount of droop. We believe that the use of this formula will increase the efficiency of trial-and-error procedures performed before mass production, enabling the manufacture of components for customers with a shorter lead time.

Root Cause Analysis of Product Service Failures in Design-A Closed-loop Lifecycle Modelling Approach

A number of industries including aerospace, telecom and automotive incur warranty and product return costs due to product malfunctions in service, which can also negatively impact customer satisfaction and loyalty. Product failures, which occur in service, are often caused by root causes at design or at manufacturing phases. Therefore a novel inter-loop modelling framework is needed which takes information from different phases to determine root causes and corrective actions. This goes beyond current intra-loop methods such as design optimization, statistical process control etc., which uses information from a single phase to address failures in the same phase. However, inter-loop modelling poses the challenge of integrating heterogeneous data from different phases of lifecycle with product and process models to determine failure root causes and corrective actions. To deal with failures in service, this paper proposes Closed-loop Lifecycle Modelling approach, specifically integrating information from service and design. Related work on fault diagnosis and corrections is also reviewed in the context of intra and inter loops of product lifecycle.The proposed methodology addresses root cause analysis (RCA) of service failures caused due to dimensional variations of product features. RCA identifies critical geometric features of internal components, which affects dimensional variations of product features. This is done by integrating warranty data from service to design models such as CAD, Geometric Dimensioning & Tolerancing (GD&T) etc. Steps of the methodology include: (i) identification of faulty product features from the Ishikawa diagram of the failure reported in warranty; (ii) variation simulation analysis of geometric features of internal components; (iii) determination of critical geometric features affecting faulty product feature via surrogate modelling of dimensional variations; and (iv) analyzing sensitivity of faulty product features on critical geometric features. The proposed Design-Service inter loop is demonstrated by an industrial case study of automotive ignition switch and ‘Sticky Key’ service failure. RCA of ‘Sticky Key’ issue identifies critical geometric features and their sensitivity in affecting the faulty product features, which cause the failure.

Modeling of Decision Making Process for Product Service Failure Diagnosis

Product malfunctions in service are addressed by service centres that diagnose the problem and make decisions on component repair or replacement actions. Feedback in the form of service centre performance in diagnosing and reparing product service failures is an important indicator of percentage of ‘First-Time-Right’ repairs, which can be improved by analytical modeling of decision making process related to fault diagnosis and repairs done by best service centres. This research proposes to develop a analytical model of service centres’ decision making process as IF-THEN decision rules which link repair actions with product pedigree. The proposed analytical model is based on Rough Sets theory and identifies decision rules which give statistically significant association between product pedigree and repair actions. Analysing the decision making process of service centres is important in developing pre-alerting fault diagnostic rules, recommending best practice diagnoses and sending feedback to OEM for potential changes in design and manufacturing. A case study from automotive warranty demonstrates the methodology.

Injuries Associated With Bottles, Pacifiers, and Sippy Cups in the United States, 1991–2010

To describe the epidemiology of injuries related to bottles, pacifiers, and sippy cups among young children in the United States. A retrospective analysis was conducted by using data from the National Electronic Injury Surveillance System for children <3 years of age treated in emergency departments (1991-2010) for an injury associated with a bottle, pacifier, or sippy cup. An estimated 45398 (95% confidence interval: 38 770-52 026) children aged <3 years were treated in emergency departments for injuries related to these products during the study period, an average of 2270 cases per year. Most injuries involved bottles (65.8%), followed by pacifiers (19.9%) and sippy cups (14.3%). The most common mechanism was a fall while using the product (86.1% of injuries). Lacerations comprised the most common diagnosis (70.4%), and the most frequently injured body region was the mouth (71.0%). One-year-old children were injured most often. Children who were aged 1 or 2 years were nearly 2.99 times (95% confidence interval: 2.07-4.33) more likely to sustain a laceration compared with any other diagnosis. Product malfunctions were relatively uncommon (4.4% of cases). This study is the first to use a nationally representative sample to examine injuries associated with these products. Given the number of injuries, particularly those associated with falls while using the product, greater efforts are needed to promote proper usage, ensure safety in product design, and increase awareness of American Academy of Pediatrics' recommendations for transitioning to a cup and discontinuing pacifier use.

THE ECONOMIC LOSS DOCTRINE: A RECOMMENDATION FOR THE SUPREME COURT OF PENNSYLVANIA

The Supreme Court of Pennsylvania should adopt the economic loss doctrine to create a clear rule for the distinction between contract and tort claims, specifically in cases of products liability. This distinction is crucial when a purchased product malfunctions, causing damage not only to itself but also to people or other property. The Supreme Court of Pennsylvania has not yet reviewed a case that would clearly create a rule in the Commonwealth for distinguishing between tort and contract claims in the sale of goods. The Third Circuit has predicted that the Supreme Court of Pennsylvania would accept the economic loss rule as adopted by the Supreme Court of the United States. However, the Superior Court of Pennsylvania has predicted that the same court will accept the “gist of the action” doctrine. To further complicate this 2

Diagnosis of Compressor Product's Malfunctions Based on Vibration Analysis

Diagnosis of Compressor Product's Malfunctions Based on Vibration Analysis

Prognostic and diagnostic monitoring of complex systems for product lifecycle management: Challenges and opportunities

Modern technological advances have resulted in a myriad of complex systems, processes and products. These increasingly complicated processes, systems and products pose considerable challenges in their design, analysis, manufacturing and management for successful operation and use over their lifecycles. In the process industries, for example, the maintenance and management of complex process equipment and processes, and their integrated operation, play a crucial role in ensuring the safety of plant personnel and the environment as well as the timely delivery of quality products. In the discrete parts industries, such as the auto industry, many product malfunctions are due to unanticipated dynamic interactions due to repeated use or misuse of components. These interactions thrive in complex systems when the combined effects of uncertainty and operational adversity are not properly addressed either in design or in operation. Given the size, scope and complexity of the systems and interactions, it is becoming increasingly difficult for plant personnel to anticipate, diagnose and control serious abnormal events in a timely manner. Hence, it should come as no surprise that human operators tend to make erroneous decisions and take actions which make matters even worse, as reported in the literature. All these cost the companies and consumers in billions of dollars every year in product lifecycle management. Businesses and federal organizations are increasingly required to manage their entire products’ lifecycles to avoid costly failure or degradation in performance through service/maintenance, more robust design and control, and so on. These product lifecycle management (PLM) issues present us with both major challenges and opportunities. There exist considerable incentives in developing appropriate prognostic and diagnostic methodologies for monitoring, analyzing, interpreting and controlling such abnormal events in complex systems and processes. People in the process and product industries view this as the next major challenge in control systems research and application. In this paper, we will present an overview of these challenges and the opportunities. Recent progress has promising implications on the use of intelligent systems for product lifecycle management applications in the chemical, petrochemical, pharmaceutical and discrete parts manufacturing industries.

212 振動分析による圧縮機の製造不良診断(セッション6 振動評価・診断)

212 振動分析による圧縮機の製造不良診断(セッション6 振動評価・診断)

Centrifugal Pump Failures

Centrifugal pumps will not pass gross quantities of gaseous emboli due to the nonocclusive nature of the pump. However, retrograde flow can occur under circumstances that include: product malfunctions, low flows, and human errors. Negative pressure created by falling arterial perfusate can draw air into the cannula. Food and Drug Administration (FDA) records about centrifugal pump malfunctions were obtained. Out of 350,000 cases completed with centrifugal pumps over a 23 month period, the FDA received reports of 68 malfunctions, 22 electrical burning smells, and three speed surges, yielding a failure rate of 1 in 3,763 cases. FDA records revealed five death reports and three serious injury reports. A survey was sent to 2,424 Society of Thoracic Surgeons' members to obtain more information; 285 who use centrifugal pumps responded. Sixty surgeons (21%) reported 108 malfunctions, including 46 complete pump failures. Fiftyone of 243 surgeons (21%) who use centrifugal pumps for bypass reported that perfusionists have forgotten to clamp the pump line, resulting in backflow. We conclude centrifugal pumps are generally safe, but malfunctions, low flows, and human errors can lead to retrograde flow and occasionally air embolization. There are valves that can be added to the bypass circuitry to prevent this risk.

Husband‐Wife Differences In Coping With Product Malfunctions

The subject of this paper is how households divide the labor of dealing with product mal functions. To date, this question has been treated only obliquely in studies of overall division of household work or consumer complaining behavior. Comparing data from both husband and wife in each of 457 households, substantial differences in the attitudes, knowledge, and behavior of spouses toward product malfunctions are found. The most important finding is that even when one controls for gender differences in the attitudes and types of knowledge which assist consumers in handling product breakdowns, husbands are consistently assigned the role of handling malfunctions. This pattern is so strong that it persists even in house holds where wives have superior resources with which to cope with product malfunctions.