Failure Mode Analysis Research Articles

Shear bond strength of MDP-containing light-cured veneer adhesive system to zirconia with different surface preparations

This study aimed to evaluate the effects of different surface preparation techniques on the surface microstructure, the shear bond strength (SBS) between zirconia and an MDP-containing light-cured veneer adhesive system, and the adhesive failure mode. Sixty-four zirconia specimens were divided into four groups based on surface preparation methods (n = 16), including zirconia sandblasting (ZSB), zirconia vitrification or glaze-on (ZVG), zirconia surface architecture technique (ZSAT), and ZSAT-ZVG combined technique (ZSATVG) groups. Sixteen lithium disilicate specimens prepared by etching with hydrofluoric acid (HF) were used as a positive control group (LDE). Surface roughness measurement and scanning electron microscopy (SEM) evaluation were performed before and after surface preparation. All specimens were then bonded with an MDP-containing light-cured adhesive system, followed by SBS testing and adhesive failure mode analysis. The ZVG and ZSATVG groups showed the greatest differential roughness value and microscopic irregularities, while the ZSAT and LDE groups had the least surface change but the most micromechanical retentive structures for resin infiltration. SBS values were significantly different among groups (p < 0.001) with the highest SBS observed in the ZSAT group, followed by the ZSB group, LDE group, ZSATVG group, and lastly, the ZVG group. There was a statistically significant difference in failure types among the surface preparation groups (p < 0.001). The ZSAT group had the highest frequency of mixed failure, followed by the ZSB group, LDE group, and the ZSATVG and ZVG groups. Establishing direct micromechanical retention within zirconia itself yields a higher bond strength than indirect micromechanical retention within a glass ceramic layer.

Effectiveness Analysis of Hydraulic Torque Wrench Machine Using Failure Mode and Effect Analysis (FMEA) and Logic Tree Analysis Study Case on Heavy Equipment Manufacturing

Production quality in terms of process efficiency and quality in the manufacturing industry must always be improved in order to maintain customer confidence. PT XYZ as a heavy equipment assembly company is one of the companies that depends on process reliability for a smooth production process. Based on this, the problems raised in this study focus on increasing the efficiency of the process of installing bolts on slew bearings. By using Overall Equipment Efficiency (OEE) and Process Capability (CpK) as the main benchmarks for measuring the quality of the production process where the latest data shows the average OEE value is at 18.53%, while the CpK value for the bolt tightening process is at 0 ,67. The OEE and CpK figures obtained show that the process quality is still not optimal and needs to be improved. The purpose of this research is to identify and prevent as many factors as possible that can lead to process failure. The methods used to evaluate processes and to identify where and how a process might fail are Failure Mode and Effect Analysis (FMEA) and Logic Tree Analysis (LTA). Both methods are used to identify and prevent as many factors as possible that can lead to a process failure. The results of research using the FMEA and LTA methods show that in the process of installing slew bearing bolts there is a process that needs to be improved because the RPN value is quite high, namely above 125. Some suggestions for improvement such as the use of a manipulator arm on a torque tool and the implementation of a manufacturing execution system (MES) can reduce the RPN value from above 125 to 28, where the process obtained is better than before.

A Vague Rough Set Approach for Failure Mode and Effect Analysis in Medical Accident

Identifying the risk factor is a key to success for the Failure model. This paper presents a new FMEA (Failure Mode and Effect Analysis) in medical accident for the hospital management by using vague rough matrix information captured through vague rough set. Using β-product and β-complement product into fuzzy relation matrix and vague set to find the new lower and upper approximation of vague rough set. This method will provide an easy methodology to find the weight of risk factor. Using an example we validate our proposed approach.

Analisis Pemborosan Waktu Pelayanan Dengan Metode Lean Healthcare Dan Failure Mode And Effects Analysis Di RSUD Dr. Soetomo Surabaya

Dr. Hospital Soetomo Surabaya with minimum service standard data that must be met is customer satisfaction ≥ 90% and waiting time ≤ 60 minutes in accordance with Ministry of Health (Kemenkes) decree no. 129 of 2008. Therefore, the problems faced by the Outpatient Institution Children's Polyclinic include service time Administration takes too long and quality must be improved. The most critical slowness of services at the Children's Polyclinic is in the registration administration section, namely the number of double registrations, disruptions in facilities and nurses who are still lacking in discipline. Applying Lean Healthcare and Failure Mode and Effects Analysis to improve service quality and prevent failures, such as slow service and lack of facilities will help find recommendations for improving these problems, namely reducing double registration of patients by improving data management and registration, repairing and improving maintenance of computer facilities for reducing waiting time due to disturbances and tightening discipline according to SOP.

Complexity for complexity-How advanced modeling may limit its applicability for decision-makers.

As today's engineering systems have become increasingly sophisticated, assessing the efficacy of their safety-critical systems has become much more challenging. The more classical methods of "failure" analysis by decomposition into components related by logic trees, such as fault and event trees, root cause analysis, and failure mode and effects analysis lead to models that do not necessarily behave like the real systems they are meant to represent. These models need to display similar emergent and unpredictable behaviors to sociotechnical systems in the real world. The question then arises as to whether a return to a simpler whole system model is necessary to understand better the behavior of real systems and to build confidence in the results. This question is more prescient when one considers that the causal chain in many serious accidents is not as deep-rooted as is sometimes claimed. If these more obvious causes are not taken away, why would the more intricate scenarios that emanate from more sophisticated models be acted upon. The paper highlights the advantages of modeling and analyzing these "normal" deviations from ideality, so called weak signals, versus just system failures and near misses as well as catastrophes. In this paper we explore this question.

Structural damage assessment and failure mode analysis for cross-fault submarine tunnels

Fault fracture zones represent unfavorable geological conditions that are often encountered in cross-sea tunnels. When such a tunnel crosses a fault, the sliding action of the fault easily results in significant tensile, compressive, and shear failure of the lining, thereby causing local buckling and even fractures. Therefore, in this study, a series of sophisticated 3D discontinuous contact numerical models were established; these models account for the underground rock stratum, hydrostatic pressure, and nonlinear behavior of materials. The developed models realistically reproduced the construction process for earth pressure balance shield tunnels, such as the jack force, grouting pressure, and grout hardening over time. The simulation results suggest that the relative spatial location and morphology of the fault fracture zone strongly influence the failure mode of the tunnel. The tunnel structure exhibits three typical failure modes: face bulge, local sliding failure, and overall sliding collapse. The dip angle and crossing angle of the fault will lead to the readjustment of shear forces and bending moments in the tunnel, leading to uneven displacement and localized torsional deformation of the adjacent lining. Additionally, increasing the ratio of diameter to thickness will decrease the overall rigidity and torsional resistance of the tunnel.

Resilience improvement of cyber-physical supply chain networks considering cascading failures with mixed failure modes

Failure mode analysis and recovery strategy improvement are critical to maintain the resilience of cyber-physical supply chain networks (CPSCNs). However, current literature mostly focuses on single failure mode and single-stage recovery strategy for CPSCNs, which may not be the case for real-world CPSCNs. In this paper, a new cascading failure model with four mixed failure modes and a joint improvement model for two-stage recovery regarding CPSCNs are proposed. A CPSCN model consisting of a weighted undirected cyber-supply network and a weighted directed physical-supply network is established to investigate the mixed cascading failures. Given the recovery requirements of practical contracts, the recovery time constraint on the enterprises in CPSCNs is considered in the joint improvement model of two-stage recovery. Based on the case studies of synthetic networks and a European supply chain network, the effects of some key factors, such as network topology and node coupling modes, on the resilience of CPSCNs are discussed. The performance of the proposed recovery strategy is compared with two traditional network recovery strategies, and the results show that the proposed strategy can help restore network performance more effectively. This work provides insights for CPSCNs recovery with resilience improvement against future cascading failures.

Analisis Kualitas Rotogravure pada Bagian Printing dengan Menggunakan Metode Failure Mode and Effect Analysis dan Fault Tree Analysis di PT. Diantrijaya Mukti Utama

One company that produces rotogravure products is PT. Diantrijaya Mukti Utama. The company implements a make to order production system. In this research, problems were found in the rotogravure production section. Namely in the form of damage to the printing machine with the average age of the machine being still young but often causing defects. The aim of this research is to identify potential failures on printing machines, find out the root causes of their occurrence on printing machines using the fault tree analysis method and produce alternative recommendations for improvement using the Failure Mode and Effect Analysis method in the printing process at PT Diantrijaya Mukti Utama. The research results showed that there were 3 types of defects in the PT printing process. Diantrijaya Mukti Utama, namely hazing defects, streaks and ink fading with a chance of defects occurring of 0.03%, 0.005%, 0.013%. Of these three defects, the causes of defects include workers being less skilled in setting the doctor blade, the doctor blade being used being damaged. Recommended improvements are to provide training related to the use of doctor blades to workers so they can know how to use and care for the doctor blades used

Application of failure mode and effect analysis in ICU admission of potentially COVID-19 infected patients

To analyze the admission and treatment process of potentially COVID-19-infected patients in the intensive care unit under normalization, prevention, and control of the pandemic. A multidisciplinary team was assembled to develop a flowchart of potentially COVID-19-infected patients admitted to the intensive care unit and identify potential failure steps and modes throughout the process using the failure mode and effect analysis method. Through risk priority number (RPN) analysis of each failure mode, those with the highest impact on nosocomial infection were identified, and the priority of implementation was determined. Related corrective measures have been developed to continuously improve clinical practice and management. Eighty potential failure modes were identified, and 8 potential failure modes were identified with RPNs greater than 100. These high RPNs of the failure modes were associated with careless inquiries of epidemiological histories by nurses, inadequate implementation of management standards by nursing assistants, and exposure of attending physicians to potentially risky environments. Finally, 18 general corrective measures are proposed. Application of the failure mode and effect analysis method for quality improvement is a powerful tool for predicting potential failures in the process and can suggest corrective measures that could help avoid nosocomial infection during a pandemic.

Solubility, Water Sorption, and Shear Bond Strength of Contemporary Pulp Capping Agents Biodentine, TheraCal LC, and Bioactive Glass Nanoparticles to the Composite Resin Restoration

Aims: Assessing the solubility, water sorption (WS), and shear bond strength (SBS) of contemporary pulp capping agents i.e., Biodentine, TheraCal LC, and Bioactive glass nanoparticles (BGn) bonded to the composite resin restoration as compared to the Dycal. Methods: Forty acrylic resin blocks with a center ditch were fabricated. Each block was then randomly allocated into four groups based on the type of pulp capping cement filled in the prepared ditch (n = 10) Group 1: Dycal, Group 2: Theracal LC, Group 3: Biodentine, and Group 4: BGn. A two-step etch and rinse adhesive along with nanohybrid universal composite were then bonded and built as a 2 mm restoration. SBS and failure mode analysis were performed using a universal testing machine (UTM) and stereomicroscope. Five disks were meticulously manufactured from each tested type of cement for solubility and WS analysis. ANOVA followed by a Tukey post hoc test evaluates the statistical significance of the SBS between restoration and pulp capping material Results: TheraCal LC exhibited the highest SBS values (7.99±0.65 MPa). However, the Dycal demonstrated the lowest bond integrity (1.46±0.19 MPa). Biodentine (14.11±0.58%) displayed the most solubility and TheraCal LC was identified as the least soluble pulp capping agent (3.99±0.41%). Biodentine (12.60±1.15%) demonstrated maximum WS whereas BGn (5.12±0.35%) unveiled the minimum WS. Conclusion: BGn cement displayed satisfactory outcomes in terms of SBS, solubility, and water sorption among all the tested cements. TheraCal LC also exhibited desirable properties of pulp capping agent. However, its water sorption is higher than Dycal.

Failure mode analysis and severity measurement method for hydropower equipment

To meet the practical needs of effective failure management and safe operation of hydropower systems, the classification and description standardization of the failure modes are studied based on the statistical analysis of historical maintenance data of in-service hydropower equipment. The method of building the failure mode library is then offered, followed by the specification of failure mode codes. Given the characteristics of the hydropower equipment, a severity rating method and the severity measurement model of failure modes for hydropower equipment are proposed, with definition criteria built using fuzzy semantic techniques. Finally, a thrust bearing system of the hydraulic generator sets is used as an example to validate the method of failure mode analysis and severity measurement, and practical suggestions for implementation of severity measurement are given in this paper.

An overview of reliability centered maintenance using failure mode and effect analysis

An overview of reliability centered maintenance using failure mode and effect analysis

An integrated risk and productivity assessment model for public–private partnership projects using fuzzy inference system

Infrastructural projects based on public–private partnership (PPP) schemes usually struggle with large amounts of resources. Given such projects’ relatively long lifetime, it is expected to encounter a wide range of risks when executing them. This implies that increasing productivity based on cost, time, and quality goals requires accurately identifying and assessing risks in these projects. This study aims at risk assessment and analysing productivity in PPP projects based on an integrated analysis method. To this end, first, library studies are utilized to identify the most significant risks by surveying the PPP-based urban underground construction projects. Expert opinions and the fuzzy Delphi (FD) technique are then employed in three stages to identify 48 secondary risk factors. By identifying the sources of these secondary risk factors, we identify five primary risk dimensions: government, financing, operation, constructability, and organization-related risks. A questionnaire is distributed to acquire experts’ opinions and screen the most critical risks by integrating FD with fuzzy failure mode and effects analysis (FFMEA). Results showed that, in total, 23 secondary risk factors in the five primary risk dimensions exhibited risk priority number (RPNNormalized) values above 0.5, indicating their relatively more critical impacts. In the next phase, a multi-stage fuzzy inference system is designed to evaluate the impacts of critical risks on the productivity of PPP projects. Output results of the inference system indicated very high, high, and medium impacts of the risks on the overall productivity of the PPP projects in terms of time, cost, and quality, respectively.

A novel quality risk evaluation framework for complex equipment development integrating PHFS-QFD and grey clustering

PurposeThe purpose of this research is to provide a theoretical framework for complex equipment quality risk evaluation. The primary aim of the framework is to enhance the ability to identify risks and improve risk control efficiency during the development phase.Design/methodology/approachA novel framework for quality risk evaluation in complex equipment is proposed, which integrates probabilistic hesitant fuzzy set-quality function deployment (PHFS-QFD) and grey clustering. PHFS-QFD is applied to identify the quality risk factors, and grey clustering is used to evaluate quality risks in cases of poor quality information during the development stage. The unfolding function of QFD is applied to simplify complex evaluation problems.FindingsThe methodology presents an innovative approach to quality risk evaluation for complex equipment development. The case analysis demonstrates that this method can efficiently evaluate the quality risks for aircraft development and systematically trace back the risk factors through hierarchical relationships. In comparison to traditional failure mode and effects analysis methods for quality risk assessment, this approach exhibits superior effectiveness and reliability in managing quality risks for complex equipment development.Originality/valueThis study contributes to the field by introducing a novel theoretical framework that combines PHFS-QFD and grey clustering. The integration of these approaches significantly improves the quality risk evaluation process for complex equipment development, overcoming challenges related to data scarcity and simplifying the assessment of intricate systems.

Failure Mode and Effects Analysis with Fuzzy TOPSIS in Fabric Dyeing Process

Kumaş boyama sürecinde çok sayıda fiziksel ve kimyasal işlem uygulanmaktadır. Ürün özelliklerine göre belirlenmesi gereken malzeme reçetelerinin ve sıcaklık, devir hızı, pH gibi parametrelerin doğru ayarlanmaması hatalara sebep olmaktadır. Bu hataların bir kısmı yeniden işleme ile giderilebilse bile operasyonel maliyetleri arttırmaktadır. Bu çalışmada, Bursa’da tekstil sektöründe faaliyet gösteren bir işletmenin boyama süreçlerinde karşılaşılan hataları belirlemek, risklerini değerlendirmek ve önceliklendirmek amacıyla bulanık TOPSIS ile Hata Türü ve Etkileri Analizi (HTEA) uygulanmaktadır. Bulanık mantık, hataların dilsel değişkenler kullanılarak değerlendirilmesini; TOPSIS ise şiddet, olasılık ve saptanabilirlik kriterlerine farklı ağırlıklar verilmesini mümkün kılmaktadır. Çalışma sonucunda hataları azaltabilecek önleyici tedbirler değerlendirilmektedir.

Effect of sodium hypochlorite-based formulations on the adhesion interface after fiber post cementation.

The study evaluated the persistence of residues, bond strength and tags formation of a cementation system after post-space irrigation with different sodium hypochlorite-based irrigants. The groups were divided according to the irrigation protocol (DW: distilled water; SHS: sodium hypochlorite solution; SHG: sodium hypochlorite gel; and, SHT: sodium hypochlorite with surfactant). Forty roots (n=10) were used to evaluate the persistence of residues by scanning electron microscopy. Other forty roots were used to the push-out bond strength test, failure mode and tag formation analyses. Non-parametric data were submitted to Kruskal Wallis and Dunn tests, while parametric data were evaluated by one-way ANOVA. No difference was observed in the persistence of residues. DW showed the highest bond strength and tag formation. Type 2 failure mode was the most frequent in the experimental groups. Compared to control, SHT showed the best performance, since less negative effects on adhesive interface was observed.

DECISION ANALYSIS FOR OPTIMAL CONCEPTUAL DESIGN OF CONCURRENT BRAKE ACTUATOR

Enhanced capabilities and customization in designs demand a thorough conceptual design phase for products or equipment. To ensure favorable outcomes, a comprehensive analysis of multiple design concepts is vital. This paper aims to conduct a decision analysis to determine the most suitable design for a concurrent brake actuator (CBA) among a range of alternative design concepts. It presents the development of the conceptual design of the CBA mechanism, which serves as a foundational mechanism design for future CBA development. Four mechanism design concepts were generated by utilizing the expanding curvature contour design, linear contour design, tilted position linear slope, and the nonlinear radius profile of the cam roller. The assessment of potential failures in the CBA concept design was performed by employing the risk priority number (RPN) within the framework of Design Failure Mode and Effects Analysis (DFMEA). The data obtained from DFMEA was utilized to conduct thorough analyses of motion and stress performance for each conceptual design using commercial software. Subsequently, the most optimal concept design for the CBA was chosen. This decision was reached by selecting the CBA concept design that achieved the highest score during the evaluation process, which employed a weighted decision matrix. According to the findings, the optimal CBA concept design was determined to be CBA Design B with the highest total score of 102 based on an RPN score is 32 and maximum stress of 3.647 x 104 N/m2. Its expanding linear contour design effectively distributes nonlinear brake force while minimizing failure risk, forming the foundational framework for future CBA development.

On the Factors That Determine the Bond Behaviour of GFRP Bars to Concrete: An Experimental Investigation

It is becoming accepted that glass-fibre-reinforced polymer (GFRP) is a credible and effective replacement for steel in reinforced concrete (RC) to meet structural requirements whilst addressing durability concerns posed by steel over the long term. A better understanding of the bond behaviour between GFRP and concrete is essential for reliably and efficiently designing concrete structures with reinforced GFRP bars. This paper presents a parametric study of the bond behaviour of GFRP bars to concrete where the effects of the length, diameter, concrete strength, concrete cover thickness and rebar surface morphology of GFRP bars were investigated via a series of pull-out tests. The test results indicate that the bond strength of GFRP bars is predominantly influenced by their surface morphology, embedment length and diameter. On the other hand, the effects of concrete strength and cover thickness appear to have a limited impact on the bond strengths of GFRP rebars to concrete. It is shown that ribbed GFRP bars exhibit the highest bond energy of 89.4 Nmm and an average bond strength of 11.9 MPa. Moreover, the analysis of failure modes indicated the unique effect of GFRP surface morphology on failure mode. It is shown that 100% of ribbed GFRP failed due to concrete split, while 85% of sand-coated bars experienced failure due to bar slip. This examination of failure modes and their corresponding bond strengths provides a unique perspective on the bond behaviour between GFRP bars and concrete.

Risk assessment based on failure mode and effects analysis (FMEA) and WASPAS methods under probabilistic double hierarchy linguistic term sets

Failure mode and effects analysis (FMEA) is regarded as an efficient tool in identifying and eliminating system failures and important tool in safety and reliability analysis. However, the traditional FMEA method has some drawbacks, for example, in the process of risk assessment, traditional FMEA method usually ignores the influence factors of weight. Simultaneously, when represent risk assessment information, crisp numbers and fuzzy sets cannot represent complex linguistic information forms accurately. Moreover, the traditional FMEA method ranks risk failures through simple product. Thus, based on these disadvantages, this paper aims to present an improved FMEA method combines with the Weighted Aggregates Sum Product Assessment (WASPAS) method and weight determination method to address the risk assessment problems under probabilistic double hierarchy linguistic (PDHL) environment. In assessment process, the probabilistic double hierarchy linguistic term sets (PDHLTSs) can indicate the probability distribution as a linguistic tool to describe the information reasonably and precisely. The contribution s of this paper can be incarnated as below. Firstly, the PDHLTSs are utilized to provide the linguistic information of failure modes and construct risk evaluation model in risk assessment. Secondly, FMEA method is combined with WASPAS method to overcoming some drawbacks existing in traditional FMEA such as without consideration of the weight of three aspects in Severity (S), Occurrence (O) and Detection (D) and too simple to evaluate the risk factors using Risk Priority Number (RPN) values. Meanwhile, in response to the issue of traditional FMEA method neglecting expert weights, weight determination method is established based on the SNA method under the PDHL context. Additionally, the FMs are ranked through the multi-attribute decision-making method WASPAS, and the final risk ranking result is obtained. Finally, the proposed method is applied to the marine risk assessment faced in the development of marine economy. Based on the assessment results, suggestions are given for the risk problems. In addition, we also carried out sensitivity analysis and accuracy analysis on the evaluation results. At the same time, comparison analysis with existing methods is given to illustrate the superiority of the proposed method.

Marine diesel engine turbocharger fouling phenomenon risk assessment application by using fuzzy FMEA method

Turbocharger fouling phenomenon was analyzed from the risk assessment perspective in this study. The research employed exhaust system and turbocharger equipment of commercial ship that equipped with a Doosan-MAN B&amp;W 6S50 MC-C diesel engine was used as the main research materials, and utilized the fuzzy Failure Mode and Effects Analysis (FMEA) based on the expert system as a methodical approach. The experts revealed different types of turbocharger fouling failure modes (FMs), along with their respective causes and subsequent consequences. Following that, the specialists allocated an O, S, and D score to each FM. Within the framework of fuzzy logic, the process entails the establishment of input and output membership functions, as well as the construction of a fuzzy model incorporating an inference mechanism and a rule base. Based on the analysis findings, the three primary factors are as follows: low cylinder compression pressure with a Fuzzy Risk Priority Number (FRPN) score of 6.95, high main engine fuel oil consumption with a score of 6.92, and high CO, CO2, SOx emissions with a 6.45. The phenomenon of turbocharger fouling, being an inherent occurrence, has significant ramifications on the main engine, the vessel as a whole, and the ecological surroundings. The quantitative results presented in this study provide valuable insights into the risks associated with maritime endeavors. The data generated from this research can be used by stakeholders in the maritime industry to better understand this situation and take proactive measures to mitigate potential risks in the future. Furthermore, the findings of the research provide corroboration for the implementation of predictive maintenance procedures.