Hydraulic-based testing and material modelling to investigate uniaxial compression of thermoset and thermoplastic polymers in quasistatic-to-dynamic regime

Hao, P.; Spronk, Siebe; Paepegem, Wim Van; Gilabert, F.A.

doi:10.1016/j.matdes.2022.111367

Cited by 10 publications

(9 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The characteristics that can be observed in the stress-strain curves are yield curves that have a clearly defined yield point, like the curves grouped by strain rate, and after unloading, ≈5% of strain is reversible. There is an intersection of the strain-stress curves due to the stress drop at strain rates of 0.1 s −1 and 0.01 s −1 at deformation ≈0.5, which is in agreement with the results for thermoplastics [75,80,81]. The stress drop is a consequence of self-heating in the case of both strain rates; heat cannot be dissipated from the surrounding area because of the speed of the process, which consequently leads to further softening of the thermo-sensitive material.…”

Section: Uniaxial Compression Testingsupporting

confidence: 90%

Thermo-Mechanical Behavior and Strain Rate Sensitivity of 3D-Printed Polylactic Acid (PLA) below Glass Transition Temperature (Tg)

Slavković,

Hanželič,

Plesec

et al. 2024

Polymers

View full text Add to dashboard Cite

This study investigated the thermomechanical behavior of 4D-printed polylactic acid (PLA), focusing on its response to varying temperatures and strain rates in a wide range below the glass transition temperature (Tg). The material was characterized using tension, compression, and dynamic mechanical thermal analysis (DMTA), confirming PLA’s strong dependency on strain rate and temperature. The glass transition temperature of 4D-printed PLA was determined to be 65 °C using a thermal analysis (DMTA). The elastic modulus changed from 1045.7 MPa in the glassy phase to 1.2 MPa in the rubber phase, showing the great shape memory potential of 4D-printed PLA. The filament tension tests revealed that the material’s yield stress strongly depended on the strain rate at room temperature, with values ranging from 56 MPa to 43 MPA as the strain rate decreased. Using a commercial FDM Ultimaker printer, cylindrical compression samples were 3D-printed and then characterized under thermo-mechanical conditions. Thermo-mechanical compression tests were conducted at strain rates ranging from 0.0001 s−1 to 0.1 s−1 and at temperatures below the glass transition temperature (Tg) at 25, 37, and 50 °C. The conducted experimental tests showed that the material had distinct yield stress, strain softening, and strain hardening at very large deformations. Clear strain rate dependence was observed, particularly at quasi-static rates, with the temperature and strain rate significantly influencing PLA’s mechanical properties, including yield stress. Yield stress values varied from 110 MPa at room temperature with a strain rate of 0.1 s−1 to 42 MPa at 50 °C with a strain rate of 0.0001 s−1. This study also included thermo-mechanical adiabatic tests, which revealed that higher strain rates of 0.01 s−1 and 0.1 s−1 led to self-heating due to non-dissipated generated heat. This internal heating caused additional softening at higher strain rates and lower stress values. Thermal imaging revealed temperature increases of 15 °C and 18 °C for strain rates of 0.01 s−1 and 0.1 s−1, respectively.

show abstract

Section: Uniaxial Compression Testingsupporting

confidence: 90%

Thermo-Mechanical Behavior and Strain Rate Sensitivity of 3D-Printed Polylactic Acid (PLA) below Glass Transition Temperature (Tg)

Slavković,

Hanželič,

Plesec

et al. 2024

Polymers

View full text Add to dashboard Cite

show abstract

“…A two-step parameter identification (PI) procedure using a (i) standard PI and (ii) SE test was employed to calibrate the material model [ 32 ]. The constrained Nelder–Mead optimization automatically retrieved the parameters

, and

by minimizing the difference between the experimental result and the simulation one.…”

Section: Thermomechanical Modelingmentioning

confidence: 99%

“…A recent developed mesoscopic-based model provides a robust identifiable relationship between the amorphous–crystalline phase interaction and the overall stress–strain response [ 29 ]. It is widely recognized that polymers are pressure-, rate- and temperature-dependent, and they also suffer from self-heating and thermal softening effects [ 30 , 31 , 32 , 33 ]. To assess the intrinsic thermomechanical response, efforts have been made using digital image correlation (DIC) for video-monitored testing [ 32 , 33 , 34 ].…”

Section: Introductionmentioning

confidence: 99%

“…It is widely recognized that polymers are pressure-, rate- and temperature-dependent, and they also suffer from self-heating and thermal softening effects [ 30 , 31 , 32 , 33 ]. To assess the intrinsic thermomechanical response, efforts have been made using digital image correlation (DIC) for video-monitored testing [ 32 , 33 , 34 ]. Poulain et al [ 34 ] showed that different video-based extensometry techniques lead to significant differences in the stress–strain responses of ductile polymers under large strains.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Advancing the Characterization of Recycled Polyolefin Blends with a Combined Experimental and Numerical Approach to Thermomechanical Behavior

Hao,

Siebers,

Ragaert

et al. 2024

Polymers

View full text Add to dashboard Cite

The blending of polyolefins (POs), such as polyethylene (PE) and polypropylene (PP), is a growing area of research, particularly for recycling mixed polyolefin (MPO) waste through flotation sorting techniques. However, understanding the thermomechanical behavior of these recycled blends is challenging due to limitations in the existing characterization methods. This paper introduces a combined experimental and numerical method to accurately assess the complex mechanical behavior of high-density PE, PP, and their blends. We conducted detailed thermomechanical analyses using a high-speed stereo digital image correlation (DIC) system paired with an infrared camera to capture temperature variations alongside mechanical stress and strain. This approach allowed us to correct for distortions caused by necking and to derive accurate stress–strain relationships. We also applied a cutting-edge unified semi-crystalline polymer (USCP) model to simplify the analysis, focusing on the effects of strain rate and temperature, including self-heating and thermal softening phenomena. Our results, which closely match experimental observations of stress–strain behavior and temperature changes, offer new insights into the thermomechanical properties of PO blends, which are essential for advancing their practical applications in various fields.

show abstract

“…The measurement of temperature increase in the samples was performed at room temperature and deformation rates of 0.01 s -1 and 0.1 s -1 . Even before the initial tests, these strain rates were identified as those for which an almost adiabatic scenario is established for thermoplastics [71][72][73][74]. Flir I7 infrared camera was used for the measurement of temperature evolution during compression tests.…”

Section: Measurement Of Temperature Change At High Strain Ratesmentioning

confidence: 99%

Thermo-Mechanical Uniaxial Compression of 4D Printed PLA in Wide Range of Strain Rates and Temperatures below Glass Transition Temperature T<sub>g</sub>

Slavković,

Hanželič,

Plesec

et al. 2024

Preprint

View full text Add to dashboard Cite

In this paper thermo-mechanical behavior of 4D printed Polylactic Acid (PLA) was investigated, focusing on its response to varying strain rates and temperatures below the glass transition temperature. Dynamic mechanical analysis and uniaxial tensile tests confirmed PLA's dependency on strain rate, showcasing its sensitivity to external stimuli. Stress-strain curves exhibited typical thermoplastic behavior, with yield stresses varying with strain rates, underscoring PLA's responsiveness to different deformation speeds. Clear strain rate dependence was observed, particularly at quasi-static rates, with temperature and strain rate fluctuations significantly influencing PLA's mechanical properties, including yield stress and deformation behavior. Isothermal compression tests demonstrated predictable stress-strain curves with distinct yield points, while adiabatic tests reveal additional complexities such as heat accumulation leading to further softening. Thermal imaging revealed temperature increase during deformation, highlighting the material's thermo-sensitive nature. These findings provide the basis for future research with the focus on advanced modeling techniques and mitigation strategies for self-heating effects, aiming to enhance PLA-based product reliability and performance in applications with deformations at higher strain rates, while also developing models to simulate shape recovery in 4D printed PLA structures at both cold and hot programming temperatures.

show abstract

Hydraulic-based testing and material modelling to investigate uniaxial compression of thermoset and thermoplastic polymers in quasistatic-to-dynamic regime

Cited by 10 publications

References 43 publications

Thermo-Mechanical Behavior and Strain Rate Sensitivity of 3D-Printed Polylactic Acid (PLA) below Glass Transition Temperature (Tg)

Thermo-Mechanical Behavior and Strain Rate Sensitivity of 3D-Printed Polylactic Acid (PLA) below Glass Transition Temperature (Tg)

Advancing the Characterization of Recycled Polyolefin Blends with a Combined Experimental and Numerical Approach to Thermomechanical Behavior

Thermo-Mechanical Uniaxial Compression of 4D Printed PLA in Wide Range of Strain Rates and Temperatures below Glass Transition Temperature T<sub>g</sub>

Contact Info

Product

Resources

About