Difference between revisions of "Steve Sharples"

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(Page edited to reflect the fact that I no longer work for the University.)
 
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<big> Applied Optics :  Steve Sharples</big>
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__NOTOC__
  
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== Where to find me ==
+
{|class="wikitable" align="right"
 +
|-
 +
|[[Image:Steve_sharples_2011.jpg‎ |link=]]
 +
|-
 +
|}
  
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Generally located in the Tower, possible locations to find me:
+
== Former Assistant Professor, Optics and Photonics Group ==
  
−
* 202 - Applied Optics Research Lab - 84-67892
+
'''Email''' ''(@nottingham.ac.uk)''''':''' stevedavid.sharples
−
* 303 - ARRO-SAM Lab - 95-15638
 
−
* 307 - Nonlinear Lab - 95-15615
 
−
* 606 - Steve's Office - 95-15220
 
−
* 306 - O-SAM Lab/Ultrasound Labs foyer - 95-15386
 
  
−
Email: steve.sharples@nottingham etc
+
I left the University of Nottingham on 30 September 2017. I still retain
 +
semi-formal ties with the research group, I am an "Associate" of the University;
 +
Matt Clark is my sponsor.
  
−
Mobile: 07976 706623
+
=== Previous research ===
  
−
== Things I do ==
+
I've worked in the field of laser ultrasonic research since 1997, and
 +
obtained my PhD, "All-Optical Scanning Acoustic Microscope" from the
 +
University of Nottingham in 2003. My research has centred around using novel
 +
laser ultrasonic techniques for materials characterisation and
 +
nondestructive evaluation (NDE). This has involved developing new
 +
techniques, new instrumentation, and new insights into the interaction of
 +
acoustic waves with materials. During the course of my PhD I improved the
 +
instrumentation to such a degree that for the first time we were able to
 +
take images – rather than single point measurements – of surface acoustic
 +
waves (SAWs) which were generated and detected using lasers. This
 +
improvement in the instrumentation led to an area of research on "Adaptive
 +
laser ultrasound with programmable optical field distributions" (2000-2003),
 +
which had profound implications for ultrasonic testing integrity. This was
 +
the study of the deleterious effects of anisotropy and microstructure on the
 +
propagation of ultrasound, and improving the methods and mechanisms to
 +
model, measure, analyse and predict this behaviour. Demonstrations of these
 +
effects led to revelations amongst many industrial (and some academic)
 +
collaborators, as it explained beautifully some of the phenomena (including
 +
unreliable data) that they had been seeing.
  
−
* Sort out [[Optics lunches]]
+
Success in this initial work led directly to a Core Project in the new
−
* Laser ultrasonics expertise, and look after the Laser Ultrasound Labs infrastructure
+
Research Centre for NDE, formed in April 2003, titled "NDE of Difficult
 +
Materials" (2003-2007). My work here used the understanding of acoustic
 +
aberration to develop techniques in three key areas. (1) Using the
 +
information gained from the effects of acoustic aberration to infer
 +
statistical properties (mean grain size, degree of anisotropy) of the
 +
material under investigation. (2) Acoustic aberration correction, whereby
 +
the aberration is detected using a multi-channel acoustic detector which I
 +
had developed, and applying correction to the generation pattern. This
 +
cancels out the effects of the microstructure, giving greater confidence and
 +
clarity for the detection of defects. (3) Development of a new technique I
 +
termed "spatially resolved acoustic spectroscopy" (SRAS) which is capable of
 +
imaging microstructure, crucial for estimating likelihood of
 +
structure-sensitive failure mechanisms. [[Matt Clark]] and I are joint inventors
 +
on the patent for this technique.
 +
 
 +
From 2007-2008 I worked on a project entitled "Advanced ultrasonic
 +
techniques for highly scattering ordered and semi-ordered materials", which
 +
involved developing techniques for rationalising the amount of information
 +
necessary to determine key properties of these complex materials (such as
 +
degree of randomness, or porosity).
 +
 
 +
I was the principal researcher working on the RCNDE Core Project, "Laser
 +
ultrasonics for the detection of damage precursors" from 2008-2012.
 +
Conventional (linear) ultrasonics is very poor at detecting changes in the
 +
material structure of a component which have an influence on its working
 +
life, prior to the formation of measurable cracks and dislocations. New
 +
techniques are being developed in order to study the relationship between
 +
fatigue and the material elastic nonlinearity – a deviation from Hooke’s
 +
Law, which describes a linear relationship between stress and strain.
 +
Although these nonlinear ultrasonic techniques are potentially much more
 +
sensitive than linear methods, measurable changes are several orders of
 +
magnitude smaller than the equivalent changes in the linear response, so
 +
they are tricky to implement.
 +
 
 +
I was the principal investigator on a 2.5 year emda (East
 +
Midlands Development Agency) and Rolls-Royce funded Technology Demonstrator
 +
project, to develop the SRAS instrumentation for materials characterisation (1 April 2010 -
 +
31 October 2012).
 +
This involved reducing the size of the SRAS instrument from one which
 +
takes up an entire optical bench, to one where all the optics could fit
 +
inside a shoebox, and to massively speed up the data acquisition, as well as
 +
providing much more quantitative data on material properties. [[Richard Smith]]
 +
was the researcher employed on this grant.
 +
 
 +
More recently I was the principal investigator on an RCNDE Core Project
 +
spanning nearly two years, entitled, “From lab to field with high frequency
 +
laser ultrasonics,” [[Roger Light]] was co-investigator. This work further developed a CMOS integrated optical
 +
sensor that I named the SKED (speckle knife edge detector), invented and
 +
developed with Roger Light. This device, combined with some fairly routine
 +
electronics and optics, has the ability to detect ultrasound on optically
 +
rough surfaces, by adapting to the speckle of the received light. A patent
 +
for this device has been filed.
 +
=== Current research ===
 +
 
 +
Current research - up to the point I left - includes a 4 year RCNDE funded project I am leading titled
 +
“NDE for Additive Manufacture”, the co-investigators are [[Matt Clark]],
 +
[http://www.nottingham.ac.uk/engineering/people/adam.clare Adam Clare] and
 +
[http://www.nottingham.ac.uk/engineering-rg/manufacturing/3dprg/people/christopher.tuck Chris Tuck].
 +
I was previously a co-investigator (Nottingham lead) on an EPSRC sponsored project titled “High deposition rate additive
 +
manufacture of complex metal parts (HiDepAM),” in collaboration with Cranfield
 +
University, who are leading this research. Both of these projects are concerned
 +
with the application of non-contact NDE methods for improving additive manufacture
 +
processes - in the case of "NDE for AM" the focus is on the selective laser melting
 +
(SLM) method (also known as "powder bed"), where the other project is focused on
 +
verifying improvements to the material properties due to improvements in the
 +
wire and arc additive manufacturing (WAAM) process developed at Cranfield
 +
University.
 +
 
 +
== Former activities and responsibilities ==
 +
 
 +
* [[Laser Safety]] Officer providing expertise, consultation and form-signing
 +
* Laser ultrasonics expertise, and look after the [[Laser Ultrasonics Lab]] (Tower 303-307) infrastructure:
 +
** [[OSAM|O-SAM and ARRO-SAM]] instruments
 +
** [[SRAS_for_materials_characterisation|SRAS]] (Spatially Resolved Acoustic Spectroscopy) for materials characterisation
 +
** [[Ultrafast]] Lab
 +
** [[%_fatigue|Nonlinear Ultrasonics]] lab
 +
** [[AO_resources#Scanning tank|Ultrasonic scanning tank]] in Tower 1007 (Main Optics Lab)
 
* Some practical RF electronics expertise (Minicircuits stuff)
 
* Some practical RF electronics expertise (Minicircuits stuff)
−
* Look after the scanning tank in Tower 201 (Main Optics Lab)
+
* Look after the main optics Linux server ("armchair"), and the [[Linux How-tos|local Linux network]], with [[Roger Light]] and [[Matt Clark|Matt]]
−
* Eagle/PCB Train expertise (see the [http://optics.eee.nottingham.ac.uk/eagle/eagle2pcbtrain.html Eagle PCB ->PCBTrain Export How-to] and the section about [[Installing locally#Eagle|installing Eagle using VPM]])
 
−
* Look after the main optics Linux server ("armchair"), and the [[Linux How-tos|local Linux network]], with help from Roger and Matt
 
−
* [[Laser Safety]] expertise, consultation and form-signing
 
−
* Look after the Linux off-site backups - see Steve or Roger for disaster recovery
 
−
* Look after the [[Printer setup|Epson AL-C3800 colour duplex printer]] in room 202
 
−
* Help maintain the Linux [[Experimental PC|control and acquisition software]], e.g.:
 
−
** [[Experimental PC#c-scan|c_scan]] (Matt mainly wrote, Roger helps to maintain)
 
−
** [http://optics.eee.nottingham.ac.uk/vxi11/ VXI-11 protocol for Linux] (general communication ethernet-enabled devices such as oscilloscopes and arbitrary function generators)
 
−
** [http://optics.eee.nottingham.ac.uk/agilent_scope/ Agilent Infiniium scopes]
 
−
** [http://optics.eee.nottingham.ac.uk/tek/ Tek scopes and AFGs]
 
−
** [http://optics.eee.nottingham.ac.uk/lecroy_tcp/ LeCroy scopes]
 
−
** [[Experimental PC#BNS SLM|BNS SLM]] (kernel driver written by Matt)
 
−
** [[Experimental PC#PI PCI stage driver|PI stages]] (kernel driver written by Matt)
 
−
** [[Experimental PC#comedi|Amplicon PCI230 DAQ comedi driver]] (mainly written by others)
 
−
* Look after the group laptop (now a Dell 12" jobbie running Windows XP)
 
−
* Look after the old group laptop, an Apple Macbook. The screen decided to spontaneously crack, and so it is now pensioned off for desktop duties (mainly video encoding). See Steve if you want to use it.
 
−
* Maintain the http://optics.eee.nottingham.ac.uk webpage
 

Latest revision as of 19:04, 2 October 2017


Steve sharples 2011.jpg

Former Assistant Professor, Optics and Photonics Group

Email (@nottingham.ac.uk): stevedavid.sharples

I left the University of Nottingham on 30 September 2017. I still retain semi-formal ties with the research group, I am an "Associate" of the University; Matt Clark is my sponsor.

Previous research

I've worked in the field of laser ultrasonic research since 1997, and obtained my PhD, "All-Optical Scanning Acoustic Microscope" from the University of Nottingham in 2003. My research has centred around using novel laser ultrasonic techniques for materials characterisation and nondestructive evaluation (NDE). This has involved developing new techniques, new instrumentation, and new insights into the interaction of acoustic waves with materials. During the course of my PhD I improved the instrumentation to such a degree that for the first time we were able to take images – rather than single point measurements – of surface acoustic waves (SAWs) which were generated and detected using lasers. This improvement in the instrumentation led to an area of research on "Adaptive laser ultrasound with programmable optical field distributions" (2000-2003), which had profound implications for ultrasonic testing integrity. This was the study of the deleterious effects of anisotropy and microstructure on the propagation of ultrasound, and improving the methods and mechanisms to model, measure, analyse and predict this behaviour. Demonstrations of these effects led to revelations amongst many industrial (and some academic) collaborators, as it explained beautifully some of the phenomena (including unreliable data) that they had been seeing.

Success in this initial work led directly to a Core Project in the new Research Centre for NDE, formed in April 2003, titled "NDE of Difficult Materials" (2003-2007). My work here used the understanding of acoustic aberration to develop techniques in three key areas. (1) Using the information gained from the effects of acoustic aberration to infer statistical properties (mean grain size, degree of anisotropy) of the material under investigation. (2) Acoustic aberration correction, whereby the aberration is detected using a multi-channel acoustic detector which I had developed, and applying correction to the generation pattern. This cancels out the effects of the microstructure, giving greater confidence and clarity for the detection of defects. (3) Development of a new technique I termed "spatially resolved acoustic spectroscopy" (SRAS) which is capable of imaging microstructure, crucial for estimating likelihood of structure-sensitive failure mechanisms. Matt Clark and I are joint inventors on the patent for this technique.

From 2007-2008 I worked on a project entitled "Advanced ultrasonic techniques for highly scattering ordered and semi-ordered materials", which involved developing techniques for rationalising the amount of information necessary to determine key properties of these complex materials (such as degree of randomness, or porosity).

I was the principal researcher working on the RCNDE Core Project, "Laser ultrasonics for the detection of damage precursors" from 2008-2012. Conventional (linear) ultrasonics is very poor at detecting changes in the material structure of a component which have an influence on its working life, prior to the formation of measurable cracks and dislocations. New techniques are being developed in order to study the relationship between fatigue and the material elastic nonlinearity – a deviation from Hooke’s Law, which describes a linear relationship between stress and strain. Although these nonlinear ultrasonic techniques are potentially much more sensitive than linear methods, measurable changes are several orders of magnitude smaller than the equivalent changes in the linear response, so they are tricky to implement.

I was the principal investigator on a 2.5 year emda (East Midlands Development Agency) and Rolls-Royce funded Technology Demonstrator project, to develop the SRAS instrumentation for materials characterisation (1 April 2010 - 31 October 2012). This involved reducing the size of the SRAS instrument from one which takes up an entire optical bench, to one where all the optics could fit inside a shoebox, and to massively speed up the data acquisition, as well as providing much more quantitative data on material properties. Richard Smith was the researcher employed on this grant.

More recently I was the principal investigator on an RCNDE Core Project spanning nearly two years, entitled, “From lab to field with high frequency laser ultrasonics,” Roger Light was co-investigator. This work further developed a CMOS integrated optical sensor that I named the SKED (speckle knife edge detector), invented and developed with Roger Light. This device, combined with some fairly routine electronics and optics, has the ability to detect ultrasound on optically rough surfaces, by adapting to the speckle of the received light. A patent for this device has been filed.

Current research

Current research - up to the point I left - includes a 4 year RCNDE funded project I am leading titled “NDE for Additive Manufacture”, the co-investigators are Matt Clark, Adam Clare and Chris Tuck. I was previously a co-investigator (Nottingham lead) on an EPSRC sponsored project titled “High deposition rate additive manufacture of complex metal parts (HiDepAM),” in collaboration with Cranfield University, who are leading this research. Both of these projects are concerned with the application of non-contact NDE methods for improving additive manufacture processes - in the case of "NDE for AM" the focus is on the selective laser melting (SLM) method (also known as "powder bed"), where the other project is focused on verifying improvements to the material properties due to improvements in the wire and arc additive manufacturing (WAAM) process developed at Cranfield University.

Former activities and responsibilities

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