A novel bio-inspired hierarchical tetrachiral structure that enhances energy absorption capacity

Pham, Duy; Huang, Shyh‐Chour

doi:10.1007/s12206-023-2202-y

Cited by 7 publications

(4 citation statements)

References 17 publications

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“…Figure 4d shows the process before and after welding the knot with UPWM. Unlike Auxetic materials, which have elastic properties of negative Poisson's ratio (NPR) [21,22], in UPWM machining, when subjected to the vertical pressure of the horn and the trigger, the material tends to change form horizontally and link two objects together through high-frequency mechanical motion [23], so the size of the weld tends to increase in the horizontal direction. The UPWM device (Linggao K745, LINGKE Inc., Zhuhai City, China) used in this study has an ultrasonic frequency of 35 kHz, a power of 900 W with an amplitude up to 40 µm (Figure 4a).…”

Section: Materials and Equipmentmentioning

confidence: 99%

Optimizing the Control Level Factors of an Ultrasonic Plastic Welding Machine Affecting the Durability of the Knots of Trawl Nets Using the Taguchi Experimental Method

Nguyen

Huang

2023

Applied Sciences

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Ultrasonic welding is a high-frequency method of welding that uses mechanical energy to generate heat. This is a clean welding method and very suitable for plastic welding. In this study, using the Taguchi experimental method, the control factors of an ultrasonic plastic welding machine were optimized to affect the durability of knots of trawl nets made from polyamide (PA) and polypropylene (PP) filaments as an alternative to the traditional mesh knitting method. After optimization, the PA knots had an amplitude of 32 µm (34%), a welding pressure of 2.5 kg/cm2 (41%), a hold time of 0.35 s (24%), and a speed of 5.5 mm/s (1%). The knots made of PP filament had relatively stable strength after optimization, with an amplitude of 36 µm (25%), a welding pressure of 2.0 kg/cm2 (22%), a hold time of 0.25 s (16%), and a speed of 6.0 mm/s (37%). Finally, validation experiments were conducted to verify the results obtained in this study.

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Section: Materials and Equipmentmentioning

confidence: 99%

Optimizing the Control Level Factors of an Ultrasonic Plastic Welding Machine Affecting the Durability of the Knots of Trawl Nets Using the Taguchi Experimental Method

Nguyen

Huang

2023

Applied Sciences

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“…The use of PLA in additive manufacturing enables the production of complex biomedical devices based on computer-aided design and construction (CAD), in particular, with the use of patient-specific anatomical data, the creation of one-of-a-kind implants [36] and prosthesis socket [37]. A new challenge in the field of additive technologies is the application of 3D printing in the production of PLA composites, with or without reinforcement [38], scaffolds [39], biodegradable stents [40] and lately in auxtic energy absorption structures [41][42][43][44][45][46][47]. PLA can also be blended with other materials such as TPU in order to show that by changing the composition and programming temperature, the desired properties for different applications can be achieved so that the highest fixity, recovery, and stress recovery were obtained in hot, cold, and warm-programmed samples by manipulating the input energy and temperature [48].…”

Section: Introductionmentioning

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

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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.

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“…The use of PLA in additive manufacturing enables the production of complex biomedical devices based on computer-aided design and construction (CAD); in particular, with the use of patient-specific anatomical data, it leads to the creation of one-of-a-kind implants [ 36 ] and prosthesis sockets [ 37 ]. A new challenge in the field of additive technologies is the application of 3D printing in the production of PLA composites, with or without reinforcement [ 38 ], scaffolds [ 39 ], biodegradable stents [ 40 ] and, lately, in auxetic energy absorption structures [ 41 , 42 , 43 , 44 , 45 , 46 , 47 ]. PLA can also be blended with other materials such as TPU in order to show that, by changing the composition and programming temperature, the desired properties for different applications can be achieved so that the highest fixity, recovery, and stress recovery are obtained in hot-, cold-, and warm-programmed samples by manipulating the input energy and temperature [ 48 ].…”

Section: Introductionmentioning

confidence: 99%

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

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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.

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A novel bio-inspired hierarchical tetrachiral structure that enhances energy absorption capacity

Cited by 7 publications

References 17 publications

Optimizing the Control Level Factors of an Ultrasonic Plastic Welding Machine Affecting the Durability of the Knots of Trawl Nets Using the Taguchi Experimental Method

Optimizing the Control Level Factors of an Ultrasonic Plastic Welding Machine Affecting the Durability of the Knots of Trawl Nets Using the Taguchi Experimental Method

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

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

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