Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Suiker's equations prevent 3-D-printed walls from collapsing or falling over

14.02.2018

3D-printed materials commonly are soft and flexible during printing, leaving printed walls susceptible to collapse or falling over. Akke Suiker, professor in Applied Mechanics at Eindhoven University of Technology, had a Eureka moment and saw the solution to this structural problem. He developed a model with which engineers can now easily determine the dimensions and printing speeds for which printed wall structures remain stable. His formulae are so elementary that they can become commonplace in the fast growing field of 3D printing.

Conventional concrete deposited in formwork typically is allowed to harden over period of several weeks. But 3D-printed concrete is not. With no supporting formwork, it almost immediately has to bear the weight of the subsequent layers of concrete that are printed on top of it.


These are rectangular shapes printed at the TU Eindhoven 3-D-concrete printer. Suiker elaborated his equations for rectangular layouts like these.

Credit: Rob Wolfs/Eindhoven University of Technology

Everybody can feel the tension rising in their body as the structure gets higher. Is it already stiff and strong enough to add yet another layer on top? It is one of the most important issues in the new field of 3D printing.

This issue was not part of the package of tasks of Professor Akke Suiker, who regularly saw the king-sized concrete printer of his university in action on the way to his office. But on a Saturday morning last March he woke up with an exciting idea how to solve the problem, already jotting down the first mathematical equations on paper during breakfast.

In the six months that follow Suiker is completely occupied by the problem, working feverishly on the details. The results are published this week in the International Journal of Mechanical Sciences (1.

Using his equations, Suiker is able to calculate how quickly he can lay down printing layers, given the material curing characteristics and wall dimensions - of course without the structure collapsing. But he can also calculate how to make the structure with as little material as possible, and what the influence of structural irregularities is.

Or what happens when he makes a wall slightly thicker or increases the material curing rate, or uses a completely different material. Or if the wall has a tendency just to fall over or also pulls the connecting structure with it. In the latter case, the consequential damage that occurs clearly is considerably greater. In fact, there are about 15 to 20 factors that one has to take into account, but because Suiker has conveniently scaled his equations, he was ultimately left with just five dimensionless parameters. Hence the problem is tackled with a very elegant and insightful model.

When asked whether his results will be important for the field of 3D printing, Suiker is without doubt. "They should be. The insights provided by the model create essential basic knowledge for everyone who prints 3D structures. For structural designers, engineering firms but also, for example, for companies that print thin-walled plastic prostheses of small dimensions, because that is where my equations also apply." The first interest is already there: he has been invited by Cambridge University to give a seminar lecture about his work.

Suiker validated his model with results of tests done with the 3D concrete printer at Eindhoven University of Technology, carried out by PhD student Rob Wolfs. He developed a computer model at the same time as Suiker, with which he can also calculate the structural behavior during the printing process, but based on the finite-element method (2. It is great for both researchers that the results from their independently developed models confirm each other.

Wolfs' model is different in terms of application. It works well for a detailed analysis of complex problems under specific printing conditions, but due to the purely numerical character and the requested computing time it is not so suitable for identifying the most important effects of the printing process, and for mapping out overall trends.

###

(1 Mechanical performance of wall structures in 3D printing processes: Theory, design tools and experiments. A.S.J. Suiker. International Journal of Mechanical Sciences

DOI: https://doi.org/10.1016/j.ijmecsci.2018.01.010

(2 Early age mechanical behaviour of 3D printed concrete: Numerical modelling and experimental testing. R.J.M. Wolfs, F.P. Bos, T.A.M. Salet, Cement and Concrete Research

DOI: https://doi.org/10.1016/j.cemconres.2018.02.001

Akke Suiker | EurekAlert!

More articles from Materials Sciences:

nachricht Scientists predict a new superhard material with unique properties
17.06.2018 | Moscow Institute of Physics and Technology

nachricht A sprinkle of platinum nanoparticles onto graphene makes brain probes more sensitive
15.06.2018 | University of California - San Diego

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

Im Focus: Photoexcited graphene puzzle solved

A boost for graphene-based light detectors

Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...

Im Focus: Water is not the same as water

Water molecules exist in two different forms with almost identical physical properties. For the first time, researchers have succeeded in separating the two forms to show that they can exhibit different chemical reactivities. These results were reported by researchers from the University of Basel and their colleagues in Hamburg in the scientific journal Nature Communications.

From a chemical perspective, water is a molecule in which a single oxygen atom is linked to two hydrogen atoms. It is less well known that water exists in two...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

A sprinkle of platinum nanoparticles onto graphene makes brain probes more sensitive

15.06.2018 | Materials Sciences

100 % Organic Farming in Bhutan – a Realistic Target?

15.06.2018 | Ecology, The Environment and Conservation

Perovskite-silicon solar cell research collaboration hits 25.2% efficiency

15.06.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>