Smoothed Particle Hydrodynamics and Adaptive Smoothed Particle Hydrodynamics with Strength of Materials

Post date: Nov 11, 2013 12:52:9 PM

This is my Master of Engineering thesis, "Smoothed Particle Hydrodynamics and Adaptive Smoothed Particle Hydrodynamics with Strength of Materials".  The file "main.pdf.original" is the original thesis that I submitted.  The file "main.pdf" is the final version with the amendments that the examiner insisted on, which I respectfully disagree with.  So please look at the original version of the thesis instead of the final submission.

The thesis contains detailed implementation details, which one would normally not find in published papers.

I did the grunt work of research and implementation independently without any assistance.  Keep in mind that in the late 1990s, one accessed journal papers mostly by making a trip to the library where the journals are kept, then going to the photocopy machine to make copies.  PDF files of journal articles downloadable from school subscribed internet access services were just starting to appear for some later papers.  It was all very labour intensive, and I still have the stacks of photocopied journal papers that I read, many of which were not eventually referenced.  National University of Singapore has most of the exotic books and journals that I needed, which was great.  Some of the books I read are much older than me.

When I started, nobody else in National University of Singapore had done any work on SPH.  In fact, even though hydrocodes have been in existence for decades, I had to formulate and implement one on my own.  I looked around literature and commercial codes to get inspiration.  All references to published materials are cited.

My thesis and published papers seem to be the only work of ASPH besides those of the original authors Owen, Villumsen, Shapiro and Martel.  Even now over a decade after I submitted my thesis, a search using Google does not reveal any other published work based on ASPH.

My thesis and published papers are the first and only work of ASPH with Strength of Materials.  Material from my thesis formed part of the book “Smoothed Particle Hydrodynamics: A Meshfree Particle Method” by G.R. Liu and M. B. Liu, published in 2003.

I need to set the record straight here.  The attached paper, which I found from Google search, "Adaptive smoothed particle hydrodynamics for high strain hydrodynamics with material strength", by M. B. Liu, G. R. Liu, K. Y. Lam, published in "Shock Waves 15 (2006)" is entirely copied from my thesis, with no new developments done.

Professor Lam Khin Yong was my supervisor, Associate Professor Liu Gui Rong was my unofficial supervisor, Liu Mou Bin was Liu Gui Rong's PhD student.  I was never told about the paper; the paper does not cite my thesis, makes only an acknowledgement of "The authors would like to acknowledge the previous work made by Mr. G. L. Chin."  This is a gloss understatement.  The paper makes no acknowledgement that I had developed ASPH with material strength, and the codes they used for the results in the paper.

The only new thing presented in this paper is to run the test cases with initial smoothing length 1.2 times the particle spacing for SPH, and h1 and h2 equal to 1.2 times the initial particle side dimension for ASPH.  Obviously this was done so that they can claim they did new work for a new paper.  My SPH and ASPH codes were run with the same input geometry files, with only a parameter change to 1.2 to produce results for a new paper!  Any one else reading the paper would have the impression that the authors developed the formulations and codes, with no idea that I was in fact the sole developer and worker.

You can compare my thesis and the paper for yourself.  I am certainly not too happy about the situation, and sad that nothing new was developed from the foundation that I created.

I am thinking of making the source code of SPH and ASPH described in my thesis available.  It consists of directories of files, which I need to clean up.  It is a lot of effort to put in copyright and license in every source file.  I am also concerned that there are dishonourable people out there who will take other people's work and claim it as their own without giving the appropriate credits due.