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Updated: 36 min 17 sec ago

Big congratulations for the well-deserved award!

Wed, 2019-12-11 18:44

In reply to 2020 Thomas J.R. Hughes Young Investigator Award - Professor Xuanhe Zhao

Dear Xuanhe,

Big congratulations for the well-deserved award!

Dear Teng,

Wed, 2019-12-11 18:06

In reply to Shape change with or without a persistent magnetic field

Dear Teng,


Thanks for the comments and insightful question. Maintaining the transformed shape without a persistent field can be very important in many applications. Your idea of bistable structures with magnetic-field trigger is a good one. Using another mechanism to maintain the transformed shape is another good idea.


To demonstrate how dynamic this field is, Ruike Zhao and Jerry Qi groups just published a paper on using shape-memory polymers to maintain the transformed shapes of ferromagnetic soft materials.


This field is rapidly evolving, with new theory, experiments, computation and applications, towards both academic and societal impacts.





Dear Stephan,

Wed, 2019-12-11 12:25

In reply to Dear Xuanhe,

Dear Stephan,

This is an excellent question. The nominal magnetization of the hard-magnetic soft materials (HMSMM is much weaker than the applied magnetic field B . Therefore, to the first order approximation, we prescribed the magnetic potential energy as -FM.B by neglecting higer order terms of M. Experimentally, we did not observe significant deformation of the HMSM due to interactions of magnetized domains alone either. More discussions on this point, can be found on Page 275 of Reference [8].

We and a few other groups are working on formulating more sophisticated constitutive models for HMSM to include effects from higher order terms. Notably, if we directly embed magnets into structures, the interactions of closeby magnets may be not negligible. 

BTW, your contribution to this field is truly remarkable and nicely summarized in this post

Look forward to seeing more exciting works on theory, experiments and applications from your group!


Why don't you extract the

Tue, 2019-12-10 14:06

In reply to XFEM

Why don't you extract the coordinates of nodes on cracked elements, then combine their PHILSM to get the current configuration of crack? It's simple math 

Hope it's not too late to reply

Tue, 2019-12-10 09:53

In reply to Hi I have the same issue

You should select the PHILSM in field output-Failure/Fracture, it should work 

Shape change with or without a persistent magnetic field

Tue, 2019-12-10 09:31

In reply to Journal Club: Magnetic Soft Materials and Robots: Design (Code), Applications and Future Directions

Dear Xuanhe,

Thanks a lot for the nice review and for highlighting the research opportunities. I have a question about the shape change design with or without a persistent magnetic field.

In the papers you cited, most of the magnetic composites will be deformed into different shapes under the external magnetic field and return to their original state after removing the magnetic field. In other words, a persistent magnetic field is required to maintain the actuated shapes. I can see this is great to design soft robots with dynamically controlled motion. For broader applications of the magnetic soft materials, one may want to maintain the new shape even after removing the external magnetic field to tune the structure properties associated with shapes (e.g., stiffness, roughness, friction, and light and sound propagation). The later design can be achieved by harnessing the bistable or multistable buckling, but also introduces additional complexity.

Could you please share your thoughts on the differences and similarities between the design of shape-changing magnetic structures with and without requiring a persistent magnetic field, in terms of applications and research challenges/opportunities for mechanics?



Dear Xuanhe,

Mon, 2019-12-09 15:51

In reply to Journal Club: Magnetic Soft Materials and Robots: Design (Code), Applications and Future Directions

Dear Xuanhe,

thank you very much for introducing the magnetic soft materials & robots.  This is a really exciting avenue for soft materials!  I will need to read the papers in detail, but will shoot a quick question: are there non-zero stresses in the "reference state" (without any external field applied) because of the intercations of the magnets?



PS: On the occation, congratulations on the Thomas J. R. Hughes Young Investigator Award! Well deserved!!!


position now filled

Mon, 2019-12-09 08:32

In reply to Postdoctoral position in computational mechanics at Duke University

This position is now filled.  Thanks to all who applied.  

To facilitate the reading and

Sun, 2019-12-08 14:34

In reply to Journal Club: Magnetic Soft Materials and Robots: Design (Code), Applications and Future Directions

To facilitate the reading and discussion, I added two more papers on examples of magnetic soft materials and robots. I also posted the slides of my talk at 2019 Fall MRS on this topic. This nascent field will use mechanics and materials as a platform to synergize recent advances in AI, 5G and robotics, potentially making a significant impact on the society. For example, prototypes of magnetic soft robots controlled by Stereotaxis system have been approved for clinical applications by FDA.


Sat, 2019-12-07 12:41

In reply to 2020 Thomas J.R. Hughes Young Investigator Award - Professor Xuanhe Zhao

Richly deserved and long overdue.

suspended pipe

Wed, 2019-12-04 05:49

In reply to A Delicate State of Instability

Very interesting finding! I guess the message is that we should look beyond the straight pipe configuration. I looked at the more exotic problem of a hose suspended to an aerostat. I guess that your finding about the horizontal offset would apply here too.

Please follow this Link

Tue, 2019-12-03 16:40

In reply to Problem During Linking

Please follow this Link procedure. Your error is related to compatibility issues of the VS and XE.





Mon, 2019-12-02 17:56

PDF of the book "An Introduction to Thermodynamics"

Mon, 2019-12-02 09:04

In reply to Dear Zhigang,

Here is the PDF of the book.

Dear Zhigang,

Sun, 2019-12-01 17:52

In reply to The algorithm of thermodynamics

Dear Zhigang,

Could you give a website for students who cann't use google?


Than You Very Much

The basic algorithm of thermodynamics

Sat, 2019-11-30 09:38

In reply to The algorithm of thermodynamics

I have expanded this lecture into a free online book (in google doc), and tested the book in a Harvard undergraduate course on thermodynamics. The approach works well.

Position of Research Fellow/Senior Research Fellow

Wed, 2019-11-27 08:38

In reply to Position of a Research Fellow/Senior Research Fellow in Computational Modelling of Damage in Li-ion Batteries

We are currently seeking to fill a position of a Research Fellow or Senior Research Fellow to contribute to a research project sponsored by EC H2020 project ‘Ecologically and Economically viable Production and Recycling of Li-ion Batteries’ (ECO2LIB) in the area of Computational Modelling of Damage in Li-ion batteries. Suitable background for candidates would include proficiency in numerical methods for simulations of crack/damage propagation, and sound background in chemo-mechanics. 


For further details please see:


Wed, 2019-11-27 03:57

In reply to I used these commands before


thank you for your answer. These commands works also when you have no user subroutine involved in the computation.

my problem is with executing from matlab a python abaqus script in which a fortran subroutine is called during the process of calculation. I guess there must be something to do with the compiler in matlab ?



I used these commands before

Tue, 2019-11-26 23:34

In reply to interfacing matlab with abaqus script using a user subroutine

I used these commands before within Matlab:

! abaqus job=input_file

! abaqus viewer

You may want to to use a similar one for Abaqus script.

Discussion of fracture paper #24 - The sound of crack growth

Thu, 2019-11-21 03:47

In reply to Discussion of fracture paper #24 - The sound of crack growth





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Dear Prof. Ståhle,

Thank you for your appreciation and interest in my paper. The analysis of the signal-based data connecting to the acoustic events arising during the damage progression seems to be a powerful way in assessing the integrity of the material.

Your concern regarding the importance of stress intensity factor and/or energy release rate is actual and plays a crucial role in the damage progression. To this scope, me and my colleagues Casavola and Pappalettera, had done subsequent research works. In one of these studies the Cohesive Zone Modelling (CZM) was analysed in the Finite Element approach to study and describe the behaviour of the CFRPs subjected to the same Mode I load (

In the meantime, the Acoustic Emission data were deeply investigated even further in understanding the damage progression in CFRPs subjected to more than one damage mode. At this purpose, the Wavelet Packet Transform (WPT) proved to be a powerful even if delicate tool in distinguishing the different damage modes. Different frequency bands of different damage modes are accounted in a CFRP using this approach (

At this moment, we are also attempting to explore other ways of identifying the damage modes in a more accurate way, by analysing the acoustic emission data according to different approaches.

Once again, I thank you for your interest in our research works. 

Claudia Barile


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