Recent Developments in ARCMAC and Related Creep Strain Monitoring Techniques

2011 ◽  
Author(s):  
Aditya Narayanan ◽  
Andy Morris ◽  
Catrin Mair Davies ◽  
John Dear
Keyword(s):  
High Temperature ◽  
Creep Strain ◽  
High Temperatures ◽  
Strain Measurement ◽  
Measurement Techniques ◽  
Image Correlation ◽  
Camera System ◽  
Full Field ◽  
Optical Strain Measurement ◽  
Optical Strain

Developments have been made to E.ON’s Auto-Reference Creep Management and Control (ARCMAC) system to measure strain at high temperature using both Digital Image Correlation (DIC) and conventional ARCMAC techniques. These techniques are aimed at measuring creep strain rate in power plant steam pipes and associated weldments operating at high temperatures and pressures for the purposes of estimation of remaining life of such components. The ARCMAC optical strain measurement system is used to measure point to point strain through the capture and analysis of images of a pair of Inconel gauges, with Silicon Nitride spheres, welded to steam pipe and other components. A modified ARCMAC image capture system has been developed using a DSLR camera, with higher resolution offering the potential to capture DIC images suitable for measuring strain accurately. Development of the system to measure strain using both ARCMAC gauges and DIC at high temperature offers the potential to obtain full-field strain measurement across features such as welds, giving a useful improved research tool for creep evaluation. The recently developed DSLR-ARCMAC camera system has been optimised to measure strain using a number of optical strain measurement techniques, including the ARCMAC strain measurement procedure and DIC. These techniques have been used to measure strain during room temperature tensile tests prior to their use at high temperatures. Following these experiments, creep testing of CMV steel specimens is planned paying particular attention to the evaluation of the ARCMAC system at high temperatures.

Assessing the Feasibility of Monitoring the Condition of Historic Tapestries Using Engineering Techniques

2007 ◽  
Vol 347 ◽  
pp. 187-192 ◽  
Author(s):  
Janice M. Dulieu-Barton ◽  
M. Sahin ◽  
F.J. Lennard ◽  
D.D. Eastop ◽  
A.R. Chambers
Keyword(s):  
Optical Fibre ◽  
Strain Measurement ◽  
Measurement Techniques ◽  
Mechanical Tests ◽  
Textile Material ◽  
Full Field ◽  
Strain Monitoring ◽  
Optical Strain Measurement ◽  
Optical Strain

The findings of a year-long programme carried out by a multidisciplinary engineering/conservation team are described. A mass-produced textile material that can be used to represent tapestries is identified and mechanical tests are detailed which demonstrate it behaves in a similar way to tapestry. The feasibility of using optical fibre sensors, full-field optical strain measurement techniques and thermography for monitoring tapestry degradation is assessed. The results of preliminary findings are presented and a rationale is developed for in-situ quantitative strain monitoring of tapestries.

Optical Strain Measurement Techniques to Assist in Life Monitoring of Power Plant Components

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Andrew Morris ◽  
Chris Maharaj ◽  
Miltiadis Kourmpetis ◽  
Ian Dear ◽  
Amit Puri ◽  
...  
Keyword(s):  
Power Plant ◽  
Creep Strain ◽  
Strain Measurement ◽  
Measurement Techniques ◽  
Image Correlation ◽  
Strain Gauges ◽  
Element Analysis ◽  
Operational Conditions ◽  
Optical Strain ◽  
Plant Components

Sensors for monitoring creep strain in high-pressure steam pipes and other power plant components are subjected to very demanding environmental and operational conditions. It is important that the sensors are of a rugged design and that measurement can be made that only relates to creep movements in power plant components. The E.ON UK auto-reference creep management and control (ARCMAC) optical strain gauges have been designed to have this capability. These optical strain gauges are installed across sections of welded steam pipe and other plant components in locations that provide the best monitoring points to reveal the early onset of failure processes. Reported in this paper are recent developments to improve optical creep strain measurement to achieve a 65 microstrain accuracy level with an error of less than 10%. Also reported are trials of combining optical strain gauges with digital image correlation (DIC) to obtain detailed information of the creep strain distribution around the gauges. The DIC data for known defect geometries have been validated with finite element analysis.

On the Calibration of Optical Full-Field Strain Measurement Systems

2006 ◽  
Vol 3-4 ◽  
pp. 397-402 ◽  
Author(s):  
Maurice P. Whelan ◽  
Erwin Hack ◽  
Thorsten Siebert ◽  
Richard L. Burguete ◽  
E.A. Patterson ◽  
...  
Keyword(s):  
Strain Measurement ◽  
Parametric Design ◽  
Image Correlation ◽  
Standard Reference Materials ◽  
Full Field ◽  
Measurement Systems ◽  
Measurement Protocol ◽  
Optical Strain Measurement ◽  
Optical Strain ◽  
Point Bend

There are no standard reference materials suitable for the calibration of full-field optical strain measurement systems. This is hindering the uptake of the technology by industrial end-users since optical metrology instrumentation and procedures cannot be easily integrated into quality assurance systems. The EU-funded SPOTS project is developing a physical reference material (PRM) and measurement protocol that should provide the basis of a calibration standard for establishing the traceability of strain values obtained with optical devices. This paper describes a PRM based on a parametric design of monolithic four-point bend test that can reliably generate a known strain field over a range of specimen sizes. Measurements acquired from strain gauges and LVDTs compared well with data obtained from ESPI, digital image correlation, photoelasticity and thermoelasticity studies, demonstrating excellent repeatability and inter-laboratory reproducibility.

Monitoring High Temperature Steam Pipes Using Optical Strain Measurement Techniques

2006 ◽  
Vol 5-6 ◽  
pp. 145-152 ◽  
Author(s):  
Andrew Morris ◽  
John P. Dear ◽  
Miltiadis Kourmpetis
Keyword(s):  
Wind Turbine ◽  
Strain Measurement ◽  
Measurement Techniques ◽  
Turbine Blades ◽  
Monitoring Methods ◽  
Wind Turbine Blades ◽  
Optical Strain Measurement ◽  
Optical Strain ◽  
High Temperature Steam ◽  
Steam Pipes

Optical strain measurement techniques have been extensively developed in recent years in order to cope in various environments. Power stations and wind turbine blades can provide challenging environments for the use of a measurement technique. There are, however, many installation problems to be overcome. For example, there is the need to have regard for the hostile environment in steam generating plant and the demanding conditions to which wind turbine blades are subjected. Ideally the outputs from individual sensors would be used for continuous remote monitoring. However, measurements can also be useful each time the plant is shut down during a plant outage; which would be used to complement data from existing proven rugged monitoring methods. This paper addresses the monitoring of pressurized steam pipes as to their micro-strain growth related to time in service. This paper presents the progress made in the developing of a ruggedised digital speckle ‘sensor’ and associated image capture system. The effect of subsurface defects in the strain distribution is examined.

Comparative Study of As-Built Geometric and Mechanical Properties of Additively Manufactured Ceramics

2018 ◽  
Author(s):  
John C. Steuben ◽  
Athanasios P. Iliopoulos ◽  
John G. Michopoulos
Keyword(s):  
Mechanical Properties ◽  
Strain Measurement ◽  
High Performance ◽  
Marked Decrease ◽  
Measurement Techniques ◽  
Direct Ink Writing ◽  
Optical Strain Measurement ◽  
Broad Variety ◽  
Optical Strain ◽  
Am Processes

Additive Manufacturing (AM) encompasses a broad variety of fabrication techniques characterized by successive additions of mass and/or energy to a build domain. AM processes have been developed for a wide variety of feedstock materials, including metals, polymers, and ceramics. In the present work we study the AM of ceramics using the Direct Ink Writing (DIW) technique. We performed comparative studies between additively manufactured and conventionally manufactured test articles, in order to quantify the variations in output geometry and mechanical properties induced by the DIW process. Uniaxial tests are conducted using high-performance optical strain measurement techniques. In particular, it is shown that the DIW-produced specimens exhibit anisotropic shrinkage when fired, as well as a marked decrease in stiffness and ultimate strength. We conclude with a discussion of potential mechanisms which may be responsible for these property degradations, and introduce potential adaptations to the DIW AM process that may be effective in combating them.

Optical Strain Monitoring Techniques

2012 ◽  
Author(s):  
Aditya Narayanan ◽  
Andy Morris ◽  
Catrin M. Davies ◽  
John P. Dear
Keyword(s):  
Digital Image Correlation ◽  
Creep Strain ◽  
Digital Image ◽  
Power Plants ◽  
Image Correlation ◽  
Camera System ◽  
Optical Strain ◽  
Point To Point ◽  
The Uk ◽  
And Control

The Auto-Reference Creep Management and Control (ARCMAC) system is being developed as a technique to evaluate the remaining life of power plant components. The system consists of a pair of Inconel plates with a configuration of silicon nitride (SiN) spheres on them, and a camera system used to take images of the gauge during the component’s deformation. The purpose of the system is to measure the creep strain accumulated by a component at regular intervals, tracking the relative motion of the spheres in order to measure a point-to-point value of strain. The system is currently used to capture images of gauges already installed on power plants in the UK as part of scheduled maintenance during plant outages. It is also possible to use the ARCMAC system to capture speckle paint pattern data used in digital image correlation (DIC) in order to visualise the strain field across the heat affected zones (HAZ) in welds and around other strain concentration features. A newer version of the system: the Digital Single Lens Reflex (DSLR) ARCMAC is being developed specifically to capture this kind of data in order to complement the point-to-point strain measurements obtained. This article presents results of experiments performed at room temperature with the purpose of establishing the basic accuracy of the conventional ARCMAC and the DSLR ARCMAC in order to compare their performance. It also intends to evaluate the performance of the latter when used for digital image correlation. The results showcase the accuracy of the technique at high strains using the DSLR camera, showing its usefulness as a tool to measure creep strain.

Optical Investigation of Component Made by FDM Technology

2016 ◽  
Vol 827 ◽  
pp. 69-72 ◽  
Author(s):  
Miroslav Jurčišin ◽  
Marek Blažo ◽  
Ján Slota
Keyword(s):  
Strain Measurement ◽  
Maximum Load ◽  
Image Correlation ◽  
Optical Investigation ◽  
Measurement Systems ◽  
Optical Strain Measurement ◽  
3D Printed ◽  
Optical Strain ◽  
Plastic Components ◽  
Complex Parts

3D printed plastic components are nowadays frequently used parts in all areas of industrial sphere. These components are often made by FDM technology. The main advantage of this technology is quick manufacturing process, price and also possibility of producing complex parts. This paper is aimed to the component made by FDM technology from the view of their strength. Specially designed chair was loaded by different force and the maximum load before destruction was measured. Chair was under inspection of two different optical strain measurement systems working on different principles. System PONTOS working on the principle of digital photogrammetry and system ARAMIS working on the principle of digital image correlation were used. These systems were used in order to investigate and identify weak places of this chair.

Damage growth and failure detection in hybrid fiber composites using experimental in-situ optical strain measurements and smoothing element analysis

2021 ◽  
pp. 105678952110451
Author(s):  
Isa Emami Tabrizi ◽  
Adnan Kefal ◽  
Jamal Seyyed Monfared Zanjani ◽  
Mehmet Yildiz
Keyword(s):  
Strain Measurement ◽  
Damage Accumulation ◽  
Failure Detection ◽  
Image Correlation ◽  
Optical Systems ◽  
Material Strength ◽  
Hybrid Fiber ◽  
Element Analysis ◽  
Optical Strain Measurement ◽  
Optical Strain

In previous study the failure initiation and development in hybrid fiber laminates was successfully monitored and determined. In current investigation a novel damage monitoring approach is proposed for hybrid laminates by combining different optical strain measurement techniques namely digital image correlation (DIC), fiber Bragg grating sensors (FBG) and infrared thermography (IRT) with smoothing element analysis (SEA). This viable experimental procedure eliminates the effects of global/local nature of optical strain measurement systems on heterogeneous damage accumulation and is a two-step approach. First, all optical sensing systems together with conventional strain gauges are utilized concurrently to indicate the differences in the measured strains and monitor damage accumulation under tensile loading. This demonstrates how failure events disturb the measurement capabilities of optical systems, which can cause a miscalculation of hybrid effect in hybrid-fiber laminates. The second step involves the utilization of SEA algorithm for discretely measured DIC displacements to predict a realistic continuous displacement/strain map and rigorously mitigate the inherent noise of the full field optical system. Remarkably, for large deformation states in hybrid composites, the combination of SEA/DIC enables early prediction of susceptible damage zones at stress levels 30% below material strength.

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