Search results for "Failure mode"
showing 10 items of 58 documents
An aging evaluation of the bearing performances of glass fiber composite laminate in salt spray fog environment
2019
The aim of the present paper is to assess the bearing performance evolution of pinned, glass-composite laminates due to environmental aging in salt-spray fog tests. Glass fibers/epoxy pinned laminates were exposed for up to 60 days in salt-spraying, foggy environmental conditions (according to ASTM B117 standard). In order to evaluate the relationship between mechanical failure mode and joint stability over increasing aging time, different single lap joints, measured by the changing hole diameter (D), laminate width (W) and hole free edge distance (E), were characterized at varying aging steps. Based on this approach, the property-structure relationship of glass-fibers/epoxy laminates was a…
Structural Behavior of Telescopic Steel Pipe for a Full-Scale 60 kW Wind Turbine Tower
2020
A simple analytical model, including local effects due to buckling and shear to moment interaction, was developed to pre-dict the load-carrying capacity of CHS tubes under flexure and shear. A finite-element analysis with ABAQUS Code was also conducted for validation of the proposed model. By properly modeling the imperfection effects due to the ovalization of steel tube, a good correlation of the structural response and failure mode was also achieved, and a good correlation with the analytical model was also achieved. Numerical and analytical results were compared with experimental results recently obtained by the author with good agreement. Experimental tests refer to full-scale static te…
Ultimate Shear of RC Beams with Corroded Stirrups and Strengthened with FRP
2019
Transverse reinforcement plays a key role in the response behavior of reinforced concrete beams. Therefore, corrosion of steel stirrups may change the failure mode of elements from bending to shear, leading to a brittle and catastrophic crisis. It is important to strengthen reinforced concrete beams with corroded stirrups to enhance the shear resistance. This paper presents a formulation, based on the modified compression field theory, to estimate the ultimate shear of reinforced concrete beams strengthened with FRP, because of stirrup corrosion. The detrimental effect of corrosion on steel stirrup yield strength was taken into account by introducing an empirical decay law. The effective st…
Nonlinear FE analysis of out-of-plane behaviour of masonry walls with and without CFRP reinforcement
2014
Abstract The out-of-plane behaviour of unreinforced and CFRP reinforced masonry wall is studied by means of experimental investigation and numerical FE modelling. The latter is based on a linear constitutive law both for ashlars and mortar joints constituting masonry and the lines of potential delamination are taken into account by means of an interface element with bi-linear law, reproducing the opening failure mode. When reinforcement is introduced, an interface element with bi-linear law is also used, reproducing sliding failure mode. Comparison between numerical and experimental results show the reliability of the modelling. Moreover, a parametric analysis is carried out in order to inv…
Experimental strength of restorations with fibre posts at different stages, with and without using a simulated ligament
2011
The aim of this study was to analyse the strength and failure mode of teeth restored with fibre posts under retention and flexural-compressive loads at different stages of the restoration and to analyse whether including a simulated ligament in the experimental setup has any effect on the strength or the failure mode. Thirty human maxillary central incisors were distributed in three different groups to be restored with simulation of different restoration stages (1: only post, 2: post and core, 3: post-core and crown), using Rebilda fibre posts. The specimens were inserted in resin blocks and loaded by means of a universal testing machine until failure under tension (stage 1) and 50o flexion…
Fracture resistance and failure mode of posterior fixed dental prostheses fabricated with two zirconia CAD/CAM systems.
2014
Background In recent years there has been an improvement of zirconia ceramic materials to replace posterior missing teeth. To date little in vitro studies has been carried out on the fracture resistance of zirconia veneered posterior fixed dental prostheses. This study investigated the fracture resistance and the failure mode of 3-unit zirconia-based posterior fixed dental prostheses fabricated with two CAD/CAM systems. Material and Methods Twenty posterior fixed dental prostheses were studied. Samples were randomly divided into two groups (n=10 each) according to the zirconia ceramic analyzed: Lava and Procera. Specimens were loaded until fracture under static load. Data were analyzed usin…
Review on the aging mechanisms in Li-ion batteries for electric vehicles based on the FMEA method
2014
With the increasing number of sold electric vehicles, the diagnosis of lithium ion traction batteries will become an important topic. For the development of diagnostic concepts, it is of high importance to have a good overview and knowledge of the internal aging mechanisms which happen inside a single cell. This paper presents a review of existing literature on this topic and summarizes the known aging mechanisms using the FMEA method (Failure Mode and Effects Analysis) in order to categorize them and establish the relationship between failure effects and causes. Based on the summarized information, new diagnostic concepts can be developed.
A Quality Risk Management Model Approach for Cell Therapy Manufacturing
2010
International regulatory authorities view risk management as an essential production need for the development of innovative, somatic cell-based therapies in regenerative medicine. The available risk management guidelines, however, provide little guidance on specific risk analysis approaches and procedures applicable in clinical cell therapy manufacturing. This raises a number of problems. Cell manufacturing is a poorly automated process, prone to operator-introduced variations, and affected by heterogeneity of the processed organs/tissues and lot-dependent variability of reagent (e.g., collagenase) efficiency. In this study, the principal challenges faced in a cell-based product manufacturi…
Assessing supply chain risks in the automotive industry through a modified MCDM-based FMECA
2020
Supply chains are complex networks that receive assiduous attention in the literature. Like any complex network, a supply chain is subject to a wide variety of risks that can result in significant economic losses and negative impacts in terms of image and prestige for companies. In circumstances of aggressive competition among companies, effective management of supply chain risks (SCRs) is crucial, and is currently a very active field of research. Failure Mode, Effects and Criticality Analysis (FMECA) has been recently extended to SCR identification and prioritization, aiming at reducing potential losses caused by lack of risk control. This article has a twofold objective. First, SCR assess…
Focus on failure avoidance and risk reduction through Variation Mode and Effect Analysis
2009
Variation Mode and Effect Analysis (VMEA) is a quality improvement tool initially thought to help product development engineers focusing on variation. The method was inspired by the wide use of Failure Mode and Effect Analysis (FMEA) in business and industry and the increased attention on robust design. However, FMEA is based on the concept of failure while VMEA is developed on the concept of variation, i.e. it implies a step further toward the awareness of variation and its implications in terms of risk and failures. VMEA helps identifying, scrutinizing and measuring the sources of variation and the way they channel through and impact on important characteristics of the system under study.…