Bond Behaviour of FRCM Composites: Effects of High Temperature

2019 ◽  
Vol 817 ◽  
pp. 161-166
Author(s):  
Antonio Iorfida ◽  
Sebastiano Candamano ◽  
Fortunato Crea ◽  
Luciano Ombres ◽  
Salvatore Verre ◽  
...  
Keyword(s):  
High Temperature ◽  
Failure Mode ◽  
Failure Modes ◽  
Construction Materials ◽  
Mechanical Damage ◽  
High Density ◽  
Bond Behaviour ◽  
Bond Slip ◽  
Masonry Construction ◽  
Lap Shear

The fire remains one of the serious potential risks to most buildings and structures, as recently it’s been witnessed in Paris’ historic Notre Dame Cathedral and London’s Grenfell Tower. Concrete and masonry construction materials suffer physiochemical changes and mechanical damage caused by heating that is usually confined to the outer surface but can eventually compromise their load-bearing capacity. FRCM systems could provide when applied, supplemental fire insulation on pre-existing structural members, but there is a lack of knowledge about their properties in those conditions. This experimental work, thus, aims to evaluate the mechanical behaviour of carbon-FRCM and basalt-FRCM composites bonded to masonry substrate after high temperature exposure. Temperatures of 100 °C, 300 °C and 500 °C over a period of three hours were used to investigate the degradation of their mechanical properties. Single lap shear bond tests were carried out to evaluate the bond-slip response and failure modes. For all the tested temperatures higher peak stresses were measured for carbon-FRCM composite than basalt ones. Furthermore, low-density basalt-FRCM composite showed higher peak stresses and lower global slips up to 300 °C than high-density one. Carbon-FRCM composite failure mode was not effected by temperature. High-density basalt-FRCM composite showed a change in failure mode between 300 °C and 500 °C.

Failure Mode Effects Analysis for Section III, Division 5 Class A, High Temperature Service of a Printed Circuit Heat Exchanger

2020 ◽  
Author(s):  
Ian Jentz ◽  
Suzanne McKillop ◽  
Robert Keating
Keyword(s):  
High Temperature ◽  
Failure Mode ◽  
Heat Exchangers ◽  
Failure Modes ◽  
Department Of Energy ◽  
Compact Heat Exchangers ◽  
Printed Circuit ◽  
Mode Effects ◽  
Class A ◽  
Asme Code

Abstract The mission of the U.S. Department of Energy (DOE), Office of Nuclear Energy is to advance nuclear power in order to meet the nation’s energy, environmental, and energy security needs. Advanced high temperature reactor systems will require compact heat exchangers (CHX) for the next generation of nuclear reactor plant designs. A necessary step for achieving this objective is to ensure that the ASME Boiler and Pressure Vessel Code, Section III, Division 5 has rules for the construction of CHXs for nuclear service. Given their high thermal efficiency and compactness, expanding the use of Alloy 800H diffusion bonded Printed Circuit Heat Exchangers (PCHEs) beyond their current application in Section VIII, Division 1 to the high temperature nuclear applications is of interest. The research being completed under the Department of Energy project is focused on preparing a draft Code Case for consideration by the ASME Code Committees for high temperature nuclear components which must meet the requirements of Section III, Division 5, Subsection HB (Class A), Subpart B. Acceptance of a Code Case by the ASME Code Committees to use PCHEs in nuclear service requires a broad understanding of PCHE failure mechanisms. At the highest level, the ASME Code requirements prevent failures of structures and pressure boundaries. Historically, the approach is a process of understanding the known failure modes, such as overload failures, plastic collapse, progressive distortion (ratcheting) and fatigue, and then establishing rules for construction to preclude those failure modes in components. For Division 5 applications, attention to differential thermal expansion, creep life, and creep-fatigue must also be considered. Failure from these loadings is manifest within PCHEs both within the internal micro-channel geometry, and at substantially larger solid header and nozzle attachments. To address the adequacy of the PCHE, a Failure Mode Effects Analysis (FMEA) has been performed for standard etched channel PCHEs. This FMEA is linked to the proposed rules in the code case for compact heat exchangers in Section III, Division 5 Class A applications. The PCHE FMEA covers all design failures addressed by Section III.

scholarly journals Application of Acoustic Emission Technique for Bond Characterization in FRP-Masonry Systems

2014 ◽  
Vol 624 ◽  
pp. 534-541 ◽  
Author(s):  
Bahman Ghiassi ◽  
Els Verstrynge ◽  
Paulo B. Lourenço ◽  
Daniel V. Oliveira
Keyword(s):  
Acoustic Emission ◽  
Failure Mode ◽  
Failure Modes ◽  
Clear Distinction ◽  
Acoustic Emission Technique ◽  
Emission Data ◽  
Bond Behavior ◽  
Damage Propagation ◽  
Lap Shear ◽  
Bond Tests

The acoustic emission (AE) technique is used for investigating the interfacial fracture and damage propagation in GFRP-and SRG-strengthened bricks during debonding tests. The bond behavior is investigated through single-lap shear bond tests and the fracture progress during the tests is recorded by means of AE sensors. The fracture progress and active debonding mechanisms are characterized in both specimen types with the aim of AE outputs. Moreover, a clear distinction between the AE outputs of specimens with different failure modes, in both SRG-and GFRP-strengthened specimens, is found which allows characterizing the debonding failure mode based on acoustic emission data.

FRCM/SRG - Masonry Joints: Experimental Investigation and Numerical Modelling

2019 ◽  
Vol 817 ◽  
pp. 3-8 ◽  
Author(s):  
Luciano Ombres ◽  
Antonio Iorfida ◽  
Salvatore Verre
Keyword(s):  
Numerical Model ◽  
Failure Modes ◽  
Shear Tests ◽  
Bond Slip ◽  
Composite Systems ◽  
Lap Shear ◽  
Commercial Code ◽  
Matrix Layer ◽  
Type Of Failure ◽  
Model Approach

The results of single-lap shear tests, performed on specimens with Fiber Reinforced Cementitious Matrix (FRCM) or Steel Reinforced Grout (SRG) composite strips bonded to masonry unit, are presented in this paper. This study indicates a different type of failure modes occur in PBO FRCM and SRG – masonry joints, respectively. The PBO-FRCM exhibited the typically telescopic failure mode while the SRG shows a slippage of the fibers and fracture of the external matrix layer at the fiber-matrix interface for both the composite systems investigated. Moreover, a 3D numerical model by the commercial code ABAQUS was realized, it is calibrated on the results present in this study. The macro model approach was used with two different bond-slip relationships present in literature. The validity of the numerical model is verified by the comparison with the experimental results in terms of the applied load-global slip and the crack patterns.

scholarly journals Influence of Bond Behaviour of Flexural GFRP Reinforcement on Failure Mechanisms in Beams Without Stirrups

2018 ◽  
Vol 64 (4) ◽  
pp. 269-283
Author(s):  
M. Kaszubska ◽  
R. Kotynia
Keyword(s):  
Shear Strength ◽  
Failure Mode ◽  
Failure Modes ◽  
Shear Failure ◽  
Shear Crack ◽  
Failure Mechanisms ◽  
Crack Pattern ◽  
Critical Crack ◽  
Bond Behaviour ◽  
Gfrp Bars

AbstractThe aim of the paper is to investigate the shear failure mechanisms in T-shape, single span and simply supported beams exclusively reinforced with longitudinal glass fiber reinforced polymer (GFRP) bars. Usually the critical shear crack in RC beams without stirrups develops through the theoretical compression strut reducing the shear strength following the shear failure. The main parameter affecting the crack pattern and the shear strength of the beams is the shear slenderness. However, the test results presented in the paper indicated the new arching effect due to the bond losing between the GFRP flexural reinforcement and concrete. This failure mode revealed unexpected critical crack pattern and failure mode. The research of concrete beams flexurally reinforced with GFRP bars without stirrups indicated two failure modes: typical shear-compression and a new one leading by the bond losing between the ordinary reinforcement and concrete.

Combine Nanoprobing Technique with Difference Analysis to Identify Nonvisual Failures

2006 ◽  
Author(s):  
Cha-Ming Shen ◽  
Tsan-Cheng Chuang ◽  
Jie-Fei Chang ◽  
Jin-Hong Chou
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
Electrical Characteristic ◽  
The Novel ◽  
Difference Analysis ◽  
Original Idea ◽  
Deductive Method ◽  
Complete Measurement

Abstract This paper presents a novel deductive methodology, which is accomplished by applying difference analysis to nano-probing technique. In order to prove the novel methodology, the specimens with 90nm process and soft failures were chosen for the experiment. The objective is to overcome the difficulty in detecting non-visual, erratic, and complex failure modes. And the original idea of this deductive method is based on the complete measurement of electrical characteristic by nano-probing and difference analysis. The capability to distinguish erratic and invisible defect was proven, even when the compound and complicated failure mode resulted in a puzzling characteristic.

Case Study and Fault Modeling for Wrong Redundancy Evaluation on DRAM Devices

2007 ◽  
Author(s):  
Martin Versen ◽  
Dorina Diaconescu ◽  
Jerome Touzel
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
Fault Modeling ◽  
Mode Analysis ◽  
Root Cause ◽  
Failure Mode Analysis

Abstract The characterization of failure modes of DRAM is often straight forward if array related hard failures with specific addresses for localization are concerned. The paper presents a case study of a bitline oriented failure mode connected to a redundancy evaluation in the DRAM periphery. The failure mode analysis and fault modeling focus both on the root-cause and on the test aspects of the problem.

Methodology for Analysis of Schottky Diode Failures

2010 ◽  
Author(s):  
Bhanu P. Sood ◽  
Michael Pecht ◽  
John Miker ◽  
Tom Wanek
Keyword(s):  
Failure Mode ◽  
Schottky Diode ◽  
Failure Modes ◽  
Schottky Diodes ◽  
Failure Mechanisms ◽  
Forward Voltage ◽  
Fast Switching ◽  
Voltage Drops ◽  
The Common

Abstract Schottky diodes are semiconductor switching devices with low forward voltage drops and very fast switching speeds. This paper provides an overview of the common failure modes in Schottky diodes and corresponding failure mechanisms associated with each failure mode. Results of material level evaluation on diodes and packages as well as manufacturing and assembly processes are analyzed to identify a set of possible failure sites with associated failure modes, mechanisms, and causes. A case study is then presented to illustrate the application of a systematic FMMEA methodology to the analysis of a specific failure in a Schottky diode package.

An Alternative to High-Temperature and Acid/Solvent-Based Methods for Removing Integrated Circuits from Ceramic or Other Problem Substrates

2005 ◽  
Author(s):  
Carl M. Nail
Keyword(s):  
High Temperature ◽  
Integrated Circuits ◽  
Success Rate ◽  
Mechanical Damage ◽  
Test Equipment ◽  
High Success Rate ◽  
Automated Test Equipment ◽  
Removal Method ◽  
Automated Test ◽  
Conventional Methods

Abstract Dice must often be removed from their packages and reassembled into more suitable packages for them to be tested in automated test equipment (ATE). Removing bare dice from their substrates using conventional methods poses risks for chemical, thermal, and/or mechanical damage. A new removal method is offered using metallography-based and parallel polishing-based techniques to remove the substrate while exposing the die to minimized risk for damage. This method has been tested and found to have a high success rate once the techniques are learned.

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