scholarly journals An Investigation Into Low Velocity Impact Of 3D Printed Thermoplastic Plates

2021 ◽  
Author(s):  
Guneet Kaur Mankoo
Keyword(s):  
Layer Thickness ◽  
High Speed ◽  
Impact Damage ◽  
Industrial Applications ◽  
Low Velocity Impact ◽  
Absorbed Energy ◽  
Damage Characteristics ◽  
3D Printed ◽  
The Impact ◽  
Clamped Edge

<div>PolyLactic Acid (PLA) is the most widely used material for 3D printing, especially in industrial applications. PLA is an environment-friendly material as it is biodegradable and has high stiffness and low cost. But PLA shows brittle nature when subjected to out-of-plane loading, i.e. impact. Hence, in this paper, a pendulum impact test apparatus was used to perform impact tests and understand the impact damage characteristics of 3D printed PLA coupons. A high-speed and an infra-red camera were used to investigate the impact damage characteristics of the coupons and understand the failure mechanisms. 24 coupons were printed on a Prusa i3 MK2S 3D printer with a 0° raster angle and different layer thickness. The layer thickness was varied from 0.10 mm to 0.18 mm and the coupons were impacted with 3 J impact energy at two different impact locations, which were, at the center and near the upper clamped edge. For impact at the center of the specimen, the absorbed energy first increased and then decreased and the coupons with higher absorbed energy showed more damage. The absorbed energy was always higher for the coupons impacted at the second location, i.e. near the clamped edge with an only exception in the case of 0.16 mm layer thickness. Coupons with 0.16 mm layer thickness had the highest absorbed energy percentage for the impact to the plate center, however for the impact near the clamped edge, 0.12 mm layer thickness had the highest absorbed energy percentage. Specimens with cracks in the direction perpendicular to the orientation absorb more energy than the specimens with cracks in the direction of extrudates. And specimens with only horizontal or vertical cracks absorb less energy than the coupons with cracks in multiple directions.</div>

scholarly journals An Investigation Into Low Velocity Impact Of 3D Printed Thermoplastic Plates

2021 ◽  
Author(s):  
Guneet Kaur Mankoo
Keyword(s):  
Layer Thickness ◽  
High Speed ◽  
Impact Damage ◽  
Industrial Applications ◽  
Low Velocity Impact ◽  
Absorbed Energy ◽  
Damage Characteristics ◽  
3D Printed ◽  
The Impact ◽  
Clamped Edge

<div>PolyLactic Acid (PLA) is the most widely used material for 3D printing, especially in industrial applications. PLA is an environment-friendly material as it is biodegradable and has high stiffness and low cost. But PLA shows brittle nature when subjected to out-of-plane loading, i.e. impact. Hence, in this paper, a pendulum impact test apparatus was used to perform impact tests and understand the impact damage characteristics of 3D printed PLA coupons. A high-speed and an infra-red camera were used to investigate the impact damage characteristics of the coupons and understand the failure mechanisms. 24 coupons were printed on a Prusa i3 MK2S 3D printer with a 0° raster angle and different layer thickness. The layer thickness was varied from 0.10 mm to 0.18 mm and the coupons were impacted with 3 J impact energy at two different impact locations, which were, at the center and near the upper clamped edge. For impact at the center of the specimen, the absorbed energy first increased and then decreased and the coupons with higher absorbed energy showed more damage. The absorbed energy was always higher for the coupons impacted at the second location, i.e. near the clamped edge with an only exception in the case of 0.16 mm layer thickness. Coupons with 0.16 mm layer thickness had the highest absorbed energy percentage for the impact to the plate center, however for the impact near the clamped edge, 0.12 mm layer thickness had the highest absorbed energy percentage. Specimens with cracks in the direction perpendicular to the orientation absorb more energy than the specimens with cracks in the direction of extrudates. And specimens with only horizontal or vertical cracks absorb less energy than the coupons with cracks in multiple directions.</div>

scholarly journals Extperimental Characterization of 3D Printed Thermoplastic Plates Subjected To Low Velocity Impact

2021 ◽  
Author(s):  
Hari Prasad Prudhvi Desu
Keyword(s):  
Energy Dissipation ◽  
Layer Thickness ◽  
Impact Damage ◽  
Low Velocity Impact ◽  
Poly Lactic Acid ◽  
Low Velocity ◽  
Velocity Impact ◽  
3D Printed ◽  
The Impact ◽  
Clamped Edge

Poly Lactic Acid (PLA) is a biodegradable material which is being extensively used in industrial applications. Due to its low glass transition temperature and cost, PLA is ideal as a feed stock in 3D printing applications. However, it has a brittle nature which makes it vulnerable to impact loads. In this paper, PLA is used to make 3D printed plates that are impact tested using an in-house low velocity impact test apparatus. A high-speed camera and an infrared thermography system are used to investigate the impact damage properties of the material. The plates manufactured with 0° orientation are used to conduct two different experiments; one with varying energies and the other with varying thickness at two different impact locations, namely at plate’s centre and close to a clamped edge. At 1 J impact energy, the plates showed a tensile crack behaviour (cracks between extrudates) and for 3 J energy it showed a mixed crack behaviour of tensile and shear (cracks along and across extrudates) with more energy dissipations than the 1 J impact. For the 1 J impact, more energy is dissipated at the centre of the plate (42.3%) than the impact close to a clamped edge (32.8%), whereas for the 3 J impact more energy is dissipated near clamped edges (97.1%) compared to the centre of the plate (54.9%). Subsequently, the 3 J impact is used for the second experiment due to the higher energy dissipation. Finally, an experimental study is conducted on plates with varied layer thickness from 0.10 mm to 0.18 mm. Results show that the increase in layer thickness (decrease in number of layers) increases the impact absorption for plates impacted at their centre. For plates impacted near their clamped edge, a zig-zag impact damage pattern of increasing and decreasing magnitudes is observed, but the energy dissipation values are higher than the centre impacted plates.

scholarly journals Extperimental Characterization of 3D Printed Thermoplastic Plates Subjected To Low Velocity Impact

2021 ◽  
Author(s):  
Hari Prasad Prudhvi Desu
Keyword(s):  
Energy Dissipation ◽  
Layer Thickness ◽  
Impact Damage ◽  
Low Velocity Impact ◽  
Poly Lactic Acid ◽  
Low Velocity ◽  
Velocity Impact ◽  
3D Printed ◽  
The Impact ◽  
Clamped Edge

Poly Lactic Acid (PLA) is a biodegradable material which is being extensively used in industrial applications. Due to its low glass transition temperature and cost, PLA is ideal as a feed stock in 3D printing applications. However, it has a brittle nature which makes it vulnerable to impact loads. In this paper, PLA is used to make 3D printed plates that are impact tested using an in-house low velocity impact test apparatus. A high-speed camera and an infrared thermography system are used to investigate the impact damage properties of the material. The plates manufactured with 0° orientation are used to conduct two different experiments; one with varying energies and the other with varying thickness at two different impact locations, namely at plate’s centre and close to a clamped edge. At 1 J impact energy, the plates showed a tensile crack behaviour (cracks between extrudates) and for 3 J energy it showed a mixed crack behaviour of tensile and shear (cracks along and across extrudates) with more energy dissipations than the 1 J impact. For the 1 J impact, more energy is dissipated at the centre of the plate (42.3%) than the impact close to a clamped edge (32.8%), whereas for the 3 J impact more energy is dissipated near clamped edges (97.1%) compared to the centre of the plate (54.9%). Subsequently, the 3 J impact is used for the second experiment due to the higher energy dissipation. Finally, an experimental study is conducted on plates with varied layer thickness from 0.10 mm to 0.18 mm. Results show that the increase in layer thickness (decrease in number of layers) increases the impact absorption for plates impacted at their centre. For plates impacted near their clamped edge, a zig-zag impact damage pattern of increasing and decreasing magnitudes is observed, but the energy dissipation values are higher than the centre impacted plates.

scholarly journals Experimental and numerical study of the response to various impact energy levels for composite sandwich plates with different face thicknesses

2019 ◽  
Vol 21 (5) ◽  
pp. 1654-1682
Author(s):  
Moeen S Rajput ◽  
Magnus Burman ◽  
Fredrik Forsberg ◽  
Stefan Hallström
Keyword(s):  
Impact Energy ◽  
Impact Damage ◽  
Energy Levels ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Absorbed Energy ◽  
Low Velocity ◽  
Composite Sandwich ◽  
The Impact ◽  
Dent Depth

Composite sandwich structures find wide application in the aerospace sector thanks to their lightweight characteristics. However, composite structures are highly susceptible to low-velocity impact damage and therefore thorough characterization of the impact response and damage process for the used material configurations is necessary. The present study investigates the effect of face-sheet thickness on the impact response and damage mechanisms, experimentally and numerically. A uni-directional, non-crimp fabric is used as reinforcement in the face-sheets, and a closed cell Rohacell 200 Hero polymer foam is used as core material. Low-velocity impact tests are performed in a novel instrumented drop-weight rig that is able to capture the true impact response. A range of impact energies are initially utilized in order to identify when low level damage (LLD), barely visible impact damage (BVID) and visible impact damage (VID) occur. A thorough fractography investigation is performed to characterize the impact damage using both destructive and non-destructive testing. The damage from the impacts in terms of dent depth, peak contact force, deflection and absorbed energy is measured. The results show bilinear responses in dent depth vs. impact energy and absorbed energy vs. impact energy. It is found than the BVID energy works well as an indication for the onset of excessive damage. Fractography reveals that there is a failure mode shift between the LLD and the VID energy levels, and that delaminations predominantly grow along the fiber direction and rotate in a spiral pattern through the thickness, following the laminate ply orientations. Finally, a progressive damage finite element model is developed to simulate both the impact response and the delamination extent, incorporating both intra-laminar and inter-laminar damage modes. The simulation shows good agreement with the experiments.

Low Velocity Impact on Fiber Reinforced Geocomposites

2016 ◽  
Vol 827 ◽  
pp. 145-148 ◽  
Author(s):  
Sneha Samal ◽  
David Reichmann ◽  
Iva Petrikova ◽  
Bohdana Marvalova
Keyword(s):  
Impact Damage ◽  
Acoustic Vibration ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Impact Behaviour ◽  
Reinforced Composite ◽  
Before And After ◽  
Two Parameters ◽  
The Impact

Low velocity impact strength of the fabric reinforced geocomposite has investigated in this article. Various fabrics such as carbon and E-glass were considered for reinforcement in geopolymer matrix. The primary two parameters such as low velocity, impact damage modes are explained on the E-glass and carbon based fabric geocomposite. The onset mode of damage to failure mode is examined through C-scan analysis. The quality of the composite is observed using c-scan with acoustic vibration mode of sensor before and after impact test. Then the effect of fabric and matrix on the impact behaviour is discussed. Residual strength of the composite is measured to determine post impact behaviour. It has been observed that resistance properties of E-glass reinforced composite is better than carbon fabric reinforced composite.

Damage Development in CFRP Laminates under Impact Loading

2006 ◽  
Vol 326-328 ◽  
pp. 1833-1836 ◽  
Author(s):  
Seung Min Jang ◽  
Tadaharu Adachi ◽  
Akihiko Yamaji
Keyword(s):  
Impact Damage ◽  
Stacking Sequence ◽  
Absorbed Energy ◽  
Damage Development ◽  
Damage Resistance ◽  
Cfrp Laminates ◽  
Impact Tester ◽  
Weight Impact ◽  
The Impact ◽  
Delamination Area

The development characteristics of impact-induced damage in carbon-fiber-reinforcedplastics (CFRP) laminates were experimentally studied using a drop-weight impact tester. Five types of CFRP laminates were used to investigate the effect of stacking sequences and thicknesses. The efficiency of absorbed energy to impact energy was different for CFRP laminates with different stacking sequences or thicknesses. The DA/AE ratio of delamination area (DA) to absorbed energy (AE) was almost the same for CFRP laminates with the same stacking sequence regardless of the thickness. We found that the DA/AE ratio could be used as a parameter to characterize the impact damage resistance in CFRP laminates with different stacking sequences.

An Adaptable Ct-Derived 3D-Printed Alignment Fixture Minimizes Errors in Whole-Bone Biomechanical Testing

2021 ◽  
Author(s):  
Jordan V. Inacio ◽  
DanielleM Cristino ◽  
Michael W. Hast ◽  
Hannah Dailey
Keyword(s):  
Computational Models ◽  
Biomechanical Testing ◽  
Ct Scanning ◽  
Industrial Applications ◽  
Long Bone ◽  
Implant Design ◽  
Orthopaedic Implant ◽  
Test Frame ◽  
3D Printed ◽  
The Impact

Abstract Biomechanical testing of long bones can be subject to undesirable errors and uncertainty due to malalignment of specimens with respect to the mechanical axis of the test frame. To solve this problem, we designed a novel, customizable alignment and potting fixture for long bone testing. The fixture consisted of 3D-printed components modeled from specimen-specific CT scans to achieve a predetermined specimen alignment. We demonstrated the functionality of this fixture by comparing benchtop torsional test results to specimen-matched finite element models and found a strong and statistically significant correlation (R2 = 0.9536, p &lt; 0.001). Additional computational models estimated the impact of malalignment on mechanical behavior in both torsion and axial compression. Results confirmed that torsion testing is relatively robust to alignment artifacts, with absolute percent errors less than 8% in all malalignment scenarios. In contrast, axial testing was highly sensitive to setup errors, experiencing absolute percent errors up to 40% with off-center malalignment and up to 130% with angular malalignment. This suggests that whenever appropriate, torsion tests should be used preferentially as a summary mechanical measure. When more challenging modes of loading are required, pre-test clinical-resolution CT scanning can be effectively used to create potting fixtures that allow for precise pre-planned specimen alignment. This may be particularly important for more sensitive biomechanical tests (e.g. axial compressive tests) that may be needed for industrial applications, such as orthopaedic implant design.

Fatigue Behavior of Impacted Plain-Weave Glass/Epoxy Composites under Tensile Fatigue Loading

2005 ◽  
Vol 297-300 ◽  
pp. 1291-1296 ◽  
Author(s):  
Ki Weon Kang ◽  
Jung Kyu Kim ◽  
Heung Seob Kim
Keyword(s):  
Fatigue Life ◽  
Impact Damage ◽  
Fatigue Behavior ◽  
Fatigue Loading ◽  
Epoxy Composites ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Damage Behavior ◽  
Plain Weave ◽  
The Impact

The goals of this paper are to identify the impact damage behavior of plain-weave E-glass/epoxy composites and predict the fatigue life of the composites with impact-induced damage under constant amplitude loading. To identify these behaviors, the low velocity impact and fatigue after impact tests are performed for glass/epoxy composites having two types of fiber orientations. The impact damage behavior is dependent on the fiber orientation of the composites. The fatigue life of the impacted composites can be identified through the prediction model, which was proposed on the carbon/epoxy laminates by authors regardless of fiber orientations.

Comparison of the impact damage resistance of non-hybrid and intra-ply hybrid carbon/E-glass/polypropylene non-crimp thermoplastic composites

2018 ◽  
Vol 38 (1) ◽  
pp. 31-45 ◽  
Author(s):  
Gaye Kaya
Keyword(s):  
Damage Tolerance ◽  
Impact Damage ◽  
Low Velocity Impact ◽  
Thermoplastic Composites ◽  
Low Velocity ◽  
Impact Properties ◽  
Compression After Impact ◽  
Post Impact ◽  
The Impact ◽  
Hybrid Carbon

This study aims to compare the low-velocity impact and post-impact properties of intra-ply hybrid carbon/E-glass/polypropylene non-crimp thermoplastic composites with non-hybrid carbon/PP and E-glass/PP non-crimp thermoplastic composites. Impact test was performed at four energy levels as 15 J, 30 J, 45 J and 60 J. Post-impact properties of hybrid thermoplastic composites were tested by compression after impact method for each energy level to understand the impact damage tolerance of intra-ply hybrid carbon/E-glass/PP non-crimp thermoplastic composites. The effect of hybridization on energy absorption of composites was not significant, while C-scan results showed that the intra-ply hybrid non-crimp thermoplastic composites had smaller impact damage areas in comparison to the non-hybrid samples. Compression and compression after impact tests results confirmed that the intra-ply hybridization increased the toughness of the composite laminates. Also, the residual compression strength/modulus increased with hybridization which indicated to damage tolerance.

scholarly journals Determination of Impact Damage in CFRP via PVDF Signal Analysis with Support Vector Machine

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5207
Author(s):  
Hyun-Taik Oh ◽  
Jong-Ick Won ◽  
Sung-Choong Woo ◽  
Tae-Won Kim
Keyword(s):  
Support Vector Machine ◽  
Vinylidene Fluoride ◽  
Impact Damage ◽  
Low Velocity Impact ◽  
Electrical Performance ◽  
Support Vector ◽  
Discrete Wavelet ◽  
Low Velocity ◽  
Damage State ◽  
The Impact

Carbon fiber reinforced plastics (CFRPs) have high specific stiffness and strength, but they are vulnerable to transverse loading, especially low-velocity impact loadings. The impact damage may cause serious strength reduction in CFRP structure, but the damage in a CFRP is mainly internal and microscopic, that it is barely visible. Therefore, this study proposes a method of determining impact damage in CFRP via poly(vinylidene fluoride) (PVDF) sensor, which is convenient and has high mechanical and electrical performance. In total, 114 drop impact tests were performed to investigate on impact responses and PVDF signals due to impacts. The test results were analyzed to determine the damage of specimens and signal features, which are relevant to failure mechanisms were extracted from PVDF signals by means of discrete wavelet transform (DWT). Support vector machine (SVM) was used for optimal classification of damage state, and the model using radial basis function (RBF) kernel showed the best performance. The model was validated through a 4-fold cross-validation, and the accuracy was reported to be 92.30%. In conclusion, impact damage in CFRP structures can be effectively determined using the spectral analysis and the machine learning-based classification on PVDF signals.

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