The short answer is yes. The mechanical properties can be calculated by means of quantum-mechanical simulations (that is, by means of what is known as first-principles calculations, nowadays often performed within the framework of the density-functional theory).

Dear Prof. Fraid,

Thank you so much for your kind support. May I know that whether there is a software like Matlab to do this calculations ?

Regards.

You are welcome Modes. No, however there are specialised first-principles packages, some of which are freely available to general public; downloading these packages often requires a formal registration with the distributor. Below I attach the link to a Wikipedia entry where these packages are listed. For orientation, I also attach the link to the PhD thesis of Maria Iuga (Würzburg, 2007) where some of the relevant issues are reviewed and discussed.

http://en.wikipedia.org/wiki/List_of_quantum_chemistry_and_solid-state_physics_software

http://d-nb.info/988262193/34

Dear Prof. Farid,

Thank you so much for sharing your time with me, although you have a tight schedule. Meanwhile the website and the dissertation were so helpful.

May I know that these packages are merely for materials with chemical bonding or there is no matter whether the bonding is chemical or physical.  ( By physical I mean just a mixture of two different powders ).

Regards. 

You are welcome Modes. These packages, insofar as they are based on the first-principles methods, do not make any assumption with regard to the chemical bonds; all they require is the position of the atoms and the type of the atom at each position; the nature of bonding follows from the quantum-mechanical calculations that these programs perform. There are other programs, capable of dealing with larger systems than the first-principles methods are capable of, which are based on empirical or semi-empirical methods and which naturally require some information regarding the nature of bonding as input. To find out about these details, you will have to consult the manuals of these programs, which are available on the relevant websites. The first-principles methods contain some parameters (such as, for instance, the extent of the unit cell and the type and nature of the basis functions to be employed) which must be chosen judiciously in order to make the calculations both feasible and reliable. For this, there are general guidelines. Nonetheless, some experience is required, which one can gain by using these programs first on some test systems about which one has considerable knowledge.

Dear Prof. Farid,

Than you so much for such this useful discussion. Thank you so much again for sharing your time with me, even though you have tight schedule. 

Regards. 

You are welcome Modes. Thank you for your kind words.

However, your discussion is not about mechanical properties, but elastic properties - that is different considerably. Please, be careful with terminology...

@ Igor L Shabalin - Some clarification of your remark would be helpful. The quantum-mechanical calculations are in principle capable of determining all mechanical properties, including elastic ones, both linear and non-linear. There are even studies of cracks and the way these propagate through the system.

Mostly the physico-mechanical properties of ceramics depend on micrograin structure of a certain material, including the structure of intergrain bondaries as an extremely important factor. This is absolutely different level in the hierarchy of matter structure in comparison with interatomic interaction and electron exchange. So, in practice of ceramic materials science and engineering the quantum-mechanical calculations could not be applied for the determination of mechanical properties of real materials. Sometimes it is useful to get the evaluation of elastic constants for ideal crystals of ceramic phases or for crystals with determined defect structure. Currently, this is the only advantage of quantum-mechanical calculations in the R&D projects on ceramics. Unfortunately, there are many students now, who used various programs without proper knowledge of fundamental sciences. In this case it looks like some kind of computer games and nothing else...

@ Igor L Shabalin - Respectfully, I disagree with you. Yes, scales do matter, and matter greatly, however from my personal perspective the issue is not a fundamental one, but a practical one: whether the fundamental unit cell of the system is not so large that it cannot be treated numerically on the computer system that one has at one's disposal (there are other practical limitations that for brevity I do not go into). That some students use programs without proper knowledge of the fundamental sciences, that is, I believe, a sociological problem and not a scientific one.

Incidentally, I have just very briefly inspected your book Ultra High Temperature Materials I (Springer, Berlin, 2014), and my understanding is that your professional approach to material science is definitely not a computational one; the approach of course is complementary to the approach by computational materials scientists; certainly I do not believe that there is any conflict between the two approaches. 

@Behnam Farid - First of all, I would like to mark that my experience in computational materials science is connected mainly with glitter (tetragonal carbon allotrope) in B-C-N system and DFT calculations of elastic constants of transition metal carbides (binary compounds of metals with carbon having cubic NaCl structure). Further, I do not claim on any conflict between the different approaches, but I would like to estimate the appropriateness of application of ab initio calculations in the area of mechanics of ceramic materials. Unfortunately, the effectiveness of these calculations for real ceramic materials is extremely poor, especially concerning strength and thermal shock resistance (mechanical!) properties. And finally, about the students: very often they are mainly victims of not ethically correct behaviour of the developers of such programs, who are promising a lot for better commercialization of the programs...

@ Igor L Shabalin - I certainly have not claimed that the available ab initio methods were perfect; if we just consider the DFT formalism, the exact functional for the exchange-correlation potential is unknown (already this is responsible for several well-known shortcomings of the DFT results in correctly predicting material properties). Then there are all kinds of problems associated with the size of the system, the choice of an inappropriate set of basis functions, etc. But from my personal perspective, all these are essentially surmountable practical problems. Things that we cannot treat accurately today, may be treatable in the next ten years or so. There are areas where since long progress would be almost impossible without some theoretical calculations (for instance, people who measure very complicated Fermi surfaces, with many different electron and hole pockets, would not be able to do their work without some band-structure calculations).  

As for the irresponsible use of computer programs by young students, personally I believe this is the fault of their scientific supervisors. It is understandable that vendors of computer programs want to promote their products and increase their sales, however this does not distract from the responsibility of the supervisor to coach his or her student properly. This is what actually graduate courses are for: to teach one's students in the methods and techniques that they are to use in their research.

In my opinion, it is not necessary to wait 10 or more years for clear understanding the fact that ab initio methods have very restricted area for the application in Materials Design. Sorry, but when you are writing about "... predicting material properties..." you are not accurate in terminology, because you are in touch with phases (physico-chemical phase has been determined strictly in thermodynamics!), but exactly not with materials. It is great difference between two fundamental terms "Phase" and "Material", though many researchers in physics and chemistry allow themselves to ignore this difference and use the word "material" very often instead of the word "phase". I know the difference very well, because in my professional career I was forced to become a materials designer, i.e. I am/was responsible for everything from an abstract idea to practical application in engineering (for me it is aerospace and nuclear engineering). I can recommend you these books:

Adams BL, Kalidindi SR, Fullwood DT, Microstructure Sensitive Design for Performance Optimization (2013) Elseveir, Amsterdam

Rajan K (ed), Informatics for Materials Science and Engineering (2013) Elsevier, Amsterdam

for some reason to revise what is the actual future of theoretical basis for Materials Science and Engineering.

Dear Prof. Shabalin ,

Dear Prof. Farid,

Thank you so much for your very nice and scientific discussions. These show me wider view of points, more clue and hints to follow the scientific and technological parts that you have mentioned. 

Regards.

@ Igor L Shabalin - It is implicitly assumed what we mean by "material properties". Even for this, understanding various "phases", one performs molecular-dynamics simulations, heating the system up and cooling it down in a controlled fashion, watching the assembly of atoms settling in their preferred stable configuration. As regards restricted area of ab initio methods, I think this is an issue over which we seem to disagree. With the so-called linear-scaling methods, when perfected, we will be able to do ab initio computations that today appear as completely out of reach. Regarding "materials", I think biology and biological processes must not be ignored. There is vast area of research regarding design of medicinal drugs, where ab initio methods can establish how drug molecules bind to various active sites of cells and modify cell behaviour.

Incidentally, for at least the past 20 years people have been using ab initio methods for the design of "materials" with desired properties. The research has been very active in the area of semiconductor technology. 

Thank you for introducing the books!

Sorry, but your phrase "...for at least the past 20 years people have been using ab initio methods for the design of "materials" with desired properties..." is a great illusion, because you have no imagination about the practice of materials design. You are too far from the frontiers of materials engineering. How many materials/compositions developed by yourself are "working" in industry...? I have got more than 40 patents on novel composite materials (mainly for rocketry), so I must correct you... Unfortunately, ab initio methods are commonly applied for... "production of thesis/dissertation", but not for engineering practice... as real appications for it are very-very-... restricted. As a conclusion: Materials Science & Engineering is a special scientific discipline, so don't mix it with Physics, Chemistry and Biology...

@ Igor L Shabalin - I am sorry to witness that you have turned a scientific discussion into an ad hominen attack on me and a self-appraisal of your contributions to materials science! What can anyone, above all I, do with the knowledge that you have apparently "40 patents on materials design"? If you wish to know my genuine response to this information: I am not impressed! Your earlier response was also replete with statements regarding your scientific and technological achievements! Please note that nowhere have I stated or implied anything that would shed doubt on your abilities and achievements, which makes it the more incomprehensible why you have felt compelled to turn the discussion into a monologue about your personal achievements. 

Frankly, having inspected your book and found the word "quantum" no more than five times in it (and only in some three tables and in the title of one reference -- "quantum chemical method" and "quantum chemistry"), with not a single mathematical equation, whether classical or quantum mechanical, in the space of some 800 pages of a book, I do not believe that you are in a position to argue with me on quantum mechanical ab initio simulations.

Now, as for ab initio materials design, you just need to do some literature search. The "at least the past 20 years" I mentioned in my previous comment, was based on a talk by Alex Zunger that I heard around 1990, that is some 25 years ago --- and 25 years ago was when simulation cells could contain at most of the order of 10 atoms. He is now member of Center for Inverse Design of the US National Renewable Energy Laboratory. 'Inverse Design' refers to their particular approach: they write down the set of properties (chemical, mechanical, optical, ...) they expect of a material and subsequently arrive at a novel material, to be grown in the laboratory, by going through an iterative cycle of self-consistent ab initio calculations. During each cycle they bring the properties of the material closer to the desired properties, by adding or removing particular atoms at particular sites, etc.

Below I attach a small selection of links which will provide you with some ideas about what people are doing in the area of materials design with the aid of ab initio simulations. 

Lastly, I do not believe that continuation of this 'discussion' will serve any scientific purpose, so let us close it here.

http://www.centerforinversedesign.org/principal_investigators.html

http://link.springer.com/article/10.1007%2Fs00339-007-4037-2

http://www.mpie.de/index.php?id=2808

http://onlinelibrary.wiley.com/doi/10.1002/9781118767061.ch6/summary

http://www.kcl.ac.uk/innovation/groups/noneqsys/PhD-projects/Indicative-PhD-Projects/Project-list/P27-Ab-initio-design-of-eco-friendly-energy-materials-with-tailored-transport-properties.aspx

Dear Prof. Farid,

Thank you so much for your nice words.

Regards. 

You are welcome Modes!

Sorry, but all the links you have mentioned above are the examples of wrong usage of the term "materials"... ("Middle in knowledge" physists and chemists would like to get funding from the basket called "Materials engineering"! A very familiar event to any reviewer in the modern research communities). Please, read the textbook on engineering materials by Ashby & Jones for clear understanding the difference between "Phase" and "Material"...

@ Igor L Shabalin - You keep saying variations of the same thing: "Unfortunately, there are many students now, who used various programs without proper knowledge of fundamental sciences.", " students: very often they are mainly victims of not ethically correct behaviour of the developers of such programs, who are promising a lot for better commercialization of the programs", and now ""Middle in knowledge" physists [sic] and chemists would like to get funding from the basket called "Materials engineering" A very familiar event to any reviewer in the modern research communities"!

As I wrote earlier, these are sociological problems, and not fundamental problems of physics. I am personally not responsible for the wrong-doings of others! There is no denying that some scientists may behave inappropriately, but this forum is not about them and the wrong things they possibly commit. This forum, in particular this very page, is about a single question posted by some one, asking: "Is there any way to calculate the mechanical properties of the ceramic composites ?". Now you are raising all kinds of sociological issues and the things in the physics community that are not to your liking! What am I supposed to do with these?

Regarding materials science, earlier I clearly emphasised that there are various ways to approach the subject matter. One is your type of approach and one other approach is based on computational simulation of the basic laws of physics applied to an assembly of atoms placed inside a simulation box. The two approaches are complementary and not mutually exclusive.

As for the difference between "phase" and "material", as I wrote earlier, in the community of physicists dealing with computational physics, the notion of "phase" is implicit in "material". You should at least try to accept that people, some of them some of the best and clearest minds on this planet, are aware of the fundamental physics and therefore cognizant of the possibility of a material being in different phases, depending on the way it has been prepared and the ambient conditions it is exposed to. More than this, I cannot say.

Dear Dr Sabalin and Dr Farid,

Forgive my intrusion in your heated discussion. But being a student learning from both sides of the fences, I have to interject here. Dr. Farid, ab initio calculations do help in understanding intrinsic material behavior at a chemical phase level. However, when it comes to building materials as a real world application especially in mechanical strength, there is no substitute for actual material product design and testing for no calculations could stimulate dynamic forces in real time interaction. I have learned through manual testing that the defects and bending behavior as an extrinsic behavior is very hard to predict. 

May I suggest a better resolution to this argument? Ab initio is a good yardstick for behavior stimulation and understanding at a molecular, but we do need material design and prototype testing for the final product (especially in mechanical strength testing). Ab initio calculations cannot stand on its own feet as the gold standard without practical material evidence through repeated material design and improvements.

Just my views on the argument. Both methods are complementary to each other, but real world application is still the final judgement of a materials mechanical behavior. Thank you.   

You can calculate mechanical properties of ceramics such as toughness using Shetty method.

Dear Dr. A. Rajabi, do you mean about this work: D.K. Shetty, I.G. Wright, P.N. Mincer and A.H. Clauer, J. Mater. Sci., 20, 1873-1882 (1985) or something different...?!

Dear Dr. A. See, unfortunately Dr. B. Farid could not understand that it was not a discussion, but only my complaints... I am an industrial materials designer, so in the relation to DFT/ab initio etc. methods I am only a user/customer/consumer/client. Thus, I am always right, when they would like to give me the "low-quality" product/goods/things, which application cannot satisfy me...

Dear Prof. Igor

yes, exactly correct. Actually, I used the formal in my paper. (Development and application of tool wear: A review of the characterization of TiC-based cermets with

different binders)

@ Igor L Shabalin - You take my words out of context. As I have repeatedly said, people misinforming others about their products is a sociological problem, not a fundamental physics problem. Misinforming potential clients and mislabelling products is a widespread problem in the human society and is not limited to the science community. The attached article ("inferior fish sold as cod and haddock ", The Guardian, 23 April 2010) is a clear point in case. 

http://www.theguardian.com/lifeandstyle/2010/apr/23/fish-fishing