APPLICATIONS

THEORY, KNOWLEDGE, & MODELS

CAPABILITIES


Drop tests on smart devices ...

Illustration: validation of an impact model for CG frames


Impact tests on Battery enclosures / protection boxes


48V battery enclosure (link to design study)

Bike components

e-bike wheels and frame in Xencor PARA LGF-1050

(Stajvelo/Domteknika)

Promotion of Xencor product family for better impact performance

The long fiber reinforced grades (Xencor) offer a higher resistance to failure propagation once the crack/notch is initiated.

 Drop test on EV charging guns

Studies conducted internally (virtual prototyping) but also applied on customer assemblies involving sub-elements made of IXEF 1022 (GC, YinRong). The difficulty is here to find the most critical position and to account for all the internal elements...

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Characterization of a strain rate dependent material model (DIGIMAT) for fiber reinforced polymers submitted to impact tests  


How to differentiate long fiber reinforced grades (Xencor) from short fiber reinforced ones in an impact simulation

In this report, we illustrate that the crack initiation occurs at the same moment for the short and long glass fiber reinforced grades. But, the long fiber grade demonstrates a much higher resistance to failure. propagation.

To account for this particularity, a progressive damage law is calibrated, using DIGIMAT, for the long fiber reinforced grade.

The model has been applied to a screen cover part (for car interior) submitted to a head impact test.




Standard impact tests such as Charpy/Izod tests or dart (multi-axial) impact tests are mainly part of the Syensqo Core Labs capabilities. The description of the related equipment can be found in the below links (core labs wikipages):

Core LabsAvailable equipment and link to description
AMC-Bollate
  • Charpy / Izod
  • Equipment at room temperature. Specimens can be conditioned from -40 to +100 °C.

Link to the Core Labs Wikipage

PCL-Alpharetta
  • Charpy / Izod (-40°C to 23°C)
  • Multi-axial Impact test (-40 °C to 100°C)

Link to the Core Labs Wikipage

PCL-Shanghai
  • Charpy / Izod
  • Drop-weight impact test

Link to the Core Labs Wikipage


The Brussels analytical Lab (Explorer Center, Haren) is also equipped with impact test capabilities. On top of pendulum impact tests and dart impact tests, this Lab has the capability to characterize the behavior of our polymers at high strain rates using a Very High Speed (VHS) tensile test machine. 

Brussels Labs equipmentDescription

Very High Speed (VHS) tensile test machine

  • Speed: up to 20m/s - Today, we can test samples from 0.1/s up to 10/s and a project is ongoing to increase this range up to 100/s.
  • Temperature range: -80°C to 250°C
  • Loading modes: tensile, shear, compression
  • Strains are measured by DIC (digital image correlation) using high speed cameras (up to 1000 000 images/s) and a specific xxx pattern pasted on the samples (in-house development).

  • The samples are so-called VHS-1-20 coupons developed internally.
  • Contact person: Siebe Spronk

The VHS machine is particularly relevant for the calibration of advanced material models to run structural simulations that take into account the effect of the strain rate as well as the fiber orientation for filled materials (see "Theory and Model" section for more details).

Dart Drop Tower

  • For coupons to medium size parts
  • Energy range: 0.57 to 1800J
  • Speed range: 0.77 to 24 m/s
  • Temperature: -70°C to 200°C
  • Compatible with high speed cameras
Charpy/Izod/Tensile impact test
  • Temperature range: -50°C to 300°C
  • Energy range (hammers): 0.5 to 25J


Some impact related test capabilities are also available in our AD Labs:

AD LabsAvailable equipment and description
Bollate
  • Ball drop test for PVDC
Alpharetta
  • NA
Shanghai
  • Ball drop test for PVDC
Fuji
  • Izod/Charpy (Instron Ceast 9050):
    • Temperature: 23°C
    • Energy levels for Izod: 2.75J, 5.5J, 11J
    • Energy levels for Charpy: 2.5J, 7.5J, 15J
  • Tensile impact strength
  • Falling weight impact test:
    • Impactor: hemispherical, D=12.7mm (steel)
    • Temperature: 23°C only
    • Energy range: up to 19.355J


Finally, some "exotic" capabilities exist on the market to measure stress-strain curves at extremely high strain rates (at 1000/s for instance). An example is the so-called "Split Hopkinson Tensile Bar" where:

  • The specimen is fixed between two different long bars (an incident bar and a transmission bar);
  • a stress wave is generated, typically by a gas gun or a striker that impacts the incident bar, and transmitted through the specimen to the transmission bar;
  • the strain in the sample is calculated by analyzing the differences between the incident, the reflected and the transmitted strain waves measured with strain gauges.

However, if the principle looks attractive on the paper, our practical experience based on different trials with external labs is less positive. Indeed, in many cases, we obtained measured stress-strain curves with a high level of noise making the post-processing and the calibration of material cards complex (and even inaccurate...).


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