scholarly journals OPTIMIZING BREAKWATER DESIGN CONSIDERING THE SYSTEM OF FAILURE MODES

2011 ◽  
Vol 1 (32) ◽  
pp. 37
Author(s):  
Alvaro Campos ◽  
Carmen Castillo ◽  
Rafael Molina
Keyword(s):  
Design Process ◽  
Failure Probability ◽  
Failure Modes ◽  
Optimization Techniques ◽  
Physical Interaction ◽  
Complete Knowledge ◽  
Potential Failure

Optimization techniques have been applied to breakwater design in order to automate the design process (Castillo et al. 2004, 2006). Since safety of structures is the fundamental criterion for design, a complete knowledge of the potential failure modes, as well as the possible interaction between them, is essential to provide a consistent design. Failure modes are correlated in two ways: through common parameters like HS or by physical interaction. The latter has not yet been precisely identified nor quantified. The aim of the present paper is to advance on the analysis of both types of correlations and to check how the combination of failure modes modifies the failure probability of the whole structure either increasing or decreasing it. An application to a special type of composite breakwater is proposed: the fuse parapet case, where part of the parapet fails under certain circumstances in order to ensure the whole stability of the caisson, despite increasing overtopping events.

Identification of Human–System Interaction Errors During Early Design Stages Using a Functional Basis Framework

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Nicolás F. Soria Zurita ◽  
Robert B. Stone ◽  
H. Onan Demirel ◽  
Irem Y. Tumer
Keyword(s):  
Design Process ◽  
Human Error ◽  
Failure Modes ◽  
Composite Function ◽  
Human System ◽  
Early Design ◽  
Functional Basis ◽  
Potential Failure ◽  
Early Design Stages ◽  
Criticality Analysis

Abstract Engineers have developed different design methodologies capable of identifying failure modes of engineering systems. The most common methods used in industry are failure modes and effects analysis, and failure modes effects and criticality analysis. Nevertheless, such methodologies have a significant limitation regarding incorporating the final user in the analysis and are not suited to identifying potential failure modes caused by physical human–system interactions. Engineering methods usually have a lack of sufficient attention to human–system interactions during the early design stages, even though introducing human factors principles is recognized as an essential analysis during the design process. As a result, designers rely on developing detailed and expensive physical or virtual prototypes to evaluate physical human–system interactions and identify potential failure modes caused by such interactions incorporating design modifications after a prototype is developed can be time-consuming, costly, and if significant changes are needed, the entire prototype requires to be constructed again. Identifying system–user interactions and possible failure modes associated with such interactions before developing a prototype can significantly improve the design process. In previous work, the authors introduced the function–human error design method (FHEDM), a tool capable of distinguishing possible human–system interaction failure modes using a functional basis framework. In this work, we examined the implementation of FHEDM within 148 products extracted from the design repository. The results are grouped in the composite function–user interaction error (FUIE) matrix, which can be used as a preliminary design database presenting information regarding the possible human error present in function-flow combinations.

scholarly journals Surface Contamination by Antineoplastics in Hospitals: An Observational Study for Mapping of Potential Contamination Associated with Handling Excreta of Babies through Diaper Management

2020 ◽  
Vol 4 (3-4) ◽  
pp. 119-125
Author(s):  
Marie Palamini ◽  
Geneviève Mercier ◽  
Jean-François Bussières
Keyword(s):  
Bone Marrow ◽  
Exploratory Study ◽  
Research Team ◽  
Failure Modes ◽  
Hospital Setting ◽  
Marrow Transplant ◽  
Mother And Child ◽  
Potential Failure ◽  
Key Steps ◽  
Hazardous Drugs

AbstractBackgroundIn the hospital setting, trace contamination with hazardous medications comes primarily from the manipulation of containers used in preparing and administering drugs. However, some traces of medications also come from the excreta of patients.MethodsThis descriptive exploratory study involved direct observation and discussion. The aim was to map potential contamination associated with handling babies’ excreta through diaper management. The study was conducted at CHU Sainte Justine (Montréal, Québec, Canada), a 500-bed mother and child facility with 38 beds for hematology-oncology and bone marrow transplant. A list of key steps related to the management of diapers by a parent or caregiver on a pediatric unit was established by the investigators. A data collection grid was then developed and reviewed by a member of the research team.ResultsA total of six diaper changes, by six distinct individuals, were observed in August and September 2019. Transport of a soiled diaper for weighing outside the baby’s room by an additional caregiver was also observed and recorded. In total, 25 individual steps in diaper management and 28 potential failure modes were identified through mapping.ConclusionsChanging a baby’s diaper involves many individual steps, which are subject to numerous failure modes that can contribute to contamination with traces of hazardous drugs. A good understanding of these process steps and failure modes is desirable to better train caregivers and parents to reduce trace contamination with hazardous drugs.

A Systematized FMEA Practice for Magnet Relays

2010 ◽  
Vol 146-147 ◽  
pp. 757-769
Author(s):  
Ching Ming Cheng ◽  
Wen Fang Wu ◽  
Yao Hsu
Keyword(s):  
New Product Development ◽  
Failure Modes ◽  
New Product ◽  
Risk Priority Number ◽  
Detection Model ◽  
Regulation Function ◽  
Potential Failure ◽  
Weighting Rule ◽  
Rating Criterion

The Design Failure Modes and Effects Analysis (DFMEA) are generally applied to risk management of New Product Development (NPD) through standardization of potential failure modes and effect-ranking of rating criterion with failure modes. Typical 1 to 10 of effect-ranking are widely weighed the priority of classification, that framing effects and status quo senses might cause decision trap happening thus. The FMEA follows considerable indexes which are including Severity, Occurrence and Detection, and need be associated with difference between every two failures individually. However, we suspect that a more systematic construction of the analysis by which failure modes belong is necessary in order to make intellectual progress in this area. Two ways of such differentiation and construction are improvable effect-ranking and systematized indexes; here we resolve for attributes of failures with classification, maturity and experiance of indexes according to an existing rule. In Severity model, the larger differentiation is achieved by separating indexes to the classification of the Law & Regulation, Function and Cosmetic. Occurrence model has its characteristic a reliable ranking indexwhich assists decisionmakers to manage their venture. This is the model most closely associate with product maturity by grouping indexes to the new, extend and series product. Detection model offers a special perspective on cost; here the connections concerned with phase occasion of the review, verification and validation. Such differentiations will be proposed and mapped with the Life Cycle Profile (LCP) to systematize FMEA. Meanwhile, a more reasonable Risk Priority Number (RPN) with the new weighting rule will be worked out for effect-ranking and management system will be integrated systematiclly

A Review on Role of Aluminum Matrix Materials, Failure Causes and Optimization Techniques

2021 ◽  
Vol 6 (3) ◽  
pp. 1-11
Author(s):  
Tilahun Y ◽  
◽  
Mesfin G ◽  
Keyword(s):  
Failure Modes ◽  
Matrix Material ◽  
Aluminum Matrix ◽  
Ductile Failure ◽  
Failure Surface ◽  
Optimization Techniques ◽  
Alloy Matrix ◽  
Modes Of Failure ◽  
Causes Of Failure

Aluminum is a metal matrix material which is widely used in different industrial as well as engineering applications.it has a great advantage due to its remarkable properties like less density, formability, and light in weight, recyclability and other properties. but, failure of aluminum matrix materials are the main problems in aluminum industries now a days.in this review role of aluminum and its alloys as matrix materials, their failure modes, causes of failure and optimization techniques to minimize this failure modes and causes of failure are discussed. Sources are reviewed which are from 2005 to recent one. Consequently, most modes of failure, causes of failure and most optimization techniques of aluminum and its alloy matrix materials are found. most modes of failure are mechanical related like fatigue failure, surface cracking, ductile failure, porosity formation, and stress related like stress corrosion cracking, surface weakness due to repeated stresses and other factors are summarized.in causes of failure mostly like corrosion formation, wear formation and poor mechanical properties are discussed.

Topology Optimization in the Conceptual Design: Take the Frame of a Bender as Example

2011 ◽  
Vol 267 ◽  
pp. 297-301
Author(s):  
Yong Wang ◽  
Guo Niu Zhu ◽  
Bo Yu Sun
Keyword(s):  
Topology Optimization ◽  
Design Process ◽  
Mechanical Design ◽  
Cost Effective ◽  
Optimization Techniques ◽  
Structural Topology Optimization ◽  
Structural Topology ◽  
Effective Manner ◽  
Stress And Deformation ◽  
Design Proposal

The paper is concerned with topology optimization in the mechanical design process. The disadvantage of current process of mechanical design is discussed and a new design process based on structural topology optimization is presented. The design process with structural topology optimization in mechanical design is discussed by the example of the frame of a bender. Static analysis is made to the original model first according to the whole structure and working characteristic of the machine, the stress and deformation distribution are obtained and then topology optimization is carried out. On the basis of topology optimization, the layout of the initial design proposal is obtained and the weight of the frame is substantially reduced while the performance enhanced. The application of the method demonstrates that through innovative utilization of the topology optimization techniques, the conceptual proposals can be obtained and the overall mechanical design process can be improved substantially in a cost effective manner.

scholarly journals Mechanism reliability and sensitivity analysis of landing gear under multiple failure modes

2021 ◽  
Vol 39 (1) ◽  
pp. 46-54
Author(s):  
Changcong Zhou ◽  
Mengyao Ji ◽  
Yishang Zhang ◽  
Fuchao Liu ◽  
Haodong Zhao
Keyword(s):  
Failure Probability ◽  
Failure Modes ◽  
Kriging Model ◽  
Landing Gear ◽  
Multiple Failure Modes ◽  
Analysis And Design ◽  
Extension System ◽  
Extension Mechanism ◽  
Assembly Error ◽  
Adaptive Kriging

For a certain type of aircraft landing gear retraction-extension mechanism, a multi-body dynamic simulation model is established, and the time-dependent curves of force and angle are obtained. Considering the random uncertainty of friction coefficient, assembly error, and the change of hinge wear under different retraction times, the reliability model is built including three failure modes of landing gear, i.e. blocking failure, positioning failure and accuracy failure. Based on the adaptive Kriging model, the reliability and sensitivity of retraction-extension system under the condition of single failure mode and multiple failure modes in series are analyzed, and the rule of reliability and sensitivity changing with the number of operations is given. The results show that the system failure probability of landing gear mechanism tends to decrease first and then increase when considering the given information of random factors, and the influences of random factors on the failure probability vary with the number of operations. This work provides a viable tool for the reliability analysis and design of landing gear mechanisms.

Structural sizing for the weight estimation of a very light aircraft wing

2018 ◽  
Vol 232 (14) ◽  
pp. 2681-2687
Author(s):  
Abdelkader Benaouali ◽  
Robert Rogólski ◽  
Stanisław Kachel
Keyword(s):  
Finite Element ◽  
Design Process ◽  
Geometric Modeling ◽  
Optimization Techniques ◽  
Product Development Process ◽  
Optimization Strategy ◽  
Aircraft Wing ◽  
Lattice Method ◽  
Vortex Lattice Method

The design process is no longer a trial-and-error procedure due to the introduction of computer-aided tools and optimization techniques. The product development process is therefore accelerated, allowing to produce more in a relatively lesser time. Moreover, the best possible design, with regard to the performance, can hence be obtained. When applied to the design of an aircraft wing, the optimization objective is usually to minimize the structural weight under failure-based constraints. This paper presents an optimization strategy that allows the determination of the wing surface structural thicknesses corresponding to the minimal weight while keeping the structure safe in terms of strength and buckling. This strategy is applied for the wing sizing process of a new two-seater very light aircraft, currently under development. The design process goes through geometric modeling, aerodynamic calculations using vortex lattice method, and finite element modeling. Structural optimization is performed within MATLAB, and is based on the automatic execution of the finite element solver MSC.NASTRAN.

Upgrading seismic performance of underground frame structures based on potential failure modes

2022 ◽  
Vol 153 ◽  
pp. 107116
Author(s):  
Chunyu Wu ◽  
Dechun Lu ◽  
M. Hesham El Naggar ◽  
Chao Ma ◽  
Qiang Li ◽  
...  
Keyword(s):  
Seismic Performance ◽  
Failure Modes ◽  
Frame Structures ◽  
Potential Failure

Static and Impact Behavior of Self-Pierced Rivet Connections in Aluminum

2001 ◽  
Author(s):  
Chelliah Madasamy ◽  
Omar Faruque ◽  
Tau Tyan ◽  
Robert Thomas
Keyword(s):  
Strain Rate ◽  
Design Process ◽  
Failure Modes ◽  
Shear Loading ◽  
Peak Force ◽  
Impact Behavior ◽  
Impact Performance ◽  
Lap Shear ◽  
Shear Modes ◽  
Importance Assessment

Abstract Self-pierced riveted (SPR) connections in aluminum coupons were tested to evaluate their static and impact performance for automotive vehicle applications. The variables studied included: top gage, bottom gage, rivet size, adhesive, pre-strain, rivet location, strain-rate, and temperature. The SPR connections were tested for coach peel, u-tension, and lap shear modes. A variable importance assessment as well as the estimated effect of the variables on peak force and energy absorption was determined. The failure modes observed during testing were consistent. From this study, it was found that the top gage, bottom gage, and temperature were very sensitive for coach peel, u-tension, and lap shear. Additionally, adhesive was found to be important for shear loading, strain-rate increased the peak force when adhesive was present and, rivet size had a significant effect on both u-tension and coach peel modes. The effect of pre-strain and rivet location was minimal, and therefore their effect in the design process can be considered minimal.

Sign in / Sign up

Export Citation Format

Share Document