scholarly journals Comparative Analysis of the Impact of Additively Manufactured Polymer Tools on the Fiber Configuration of Injection Molded Long-Fiber-Reinforced Thermoplastics

2020 ◽  
Vol 4 (3) ◽  
pp. 136
Author(s):  
Lukas Knorr ◽  
Robert Setter ◽  
Dominik Rietzel ◽  
Katrin Wudy ◽  
Tim Osswald
Keyword(s):  
Mechanical Properties ◽  
Failure Modes ◽  
Quality Criteria ◽  
Life Cycles ◽  
Fiber Reinforced ◽  
Fiber Concentration ◽  
Cycle Number ◽  
Geometrical Accuracy ◽  
Small Series ◽  
The Impact

Additive tooling (AT) utilizes the advantages of rapid tooling development while minimizing geometrical limitations of conventional tool manufacturing such as complex design of cooling channels. This investigation presents a comparative experimental analysis of long-fiber-reinforced thermoplastic parts (LFTs), which are produced through additively manufactured injection molding polymer tools. After giving a review on the state of the art of AT and LFTs, additive manufacturing (AM) plastic tools are compared to conventionally manufactured steel and aluminum tools toward their qualification for spare part and small series production as well as functional validation. The assessment of the polymer tools focuses on three quality criteria concerning the LFT parts: geometrical accuracy, mechanical properties, and fiber configuration. The analysis of the fiber configuration includes fiber length, fiber concentration, and fiber orientation. The results show that polymer tools are fully capable of manufacturing LFTs with a cycle number within hundreds before showing critical signs of deterioration or tool failure. The produced LFTs moldings provide sufficient quality in geometrical accuracy, mechanical properties, and fiber configuration. Further, specific anomalies of the fiber configuration can be detected for all tool types, which include the occurrence of characteristic zones dependent on the nominal fiber content and melt flow distance. Conclusions toward the improvement of additively manufactured polymer tool life cycles are drawn based on the detected deteriorations and failure modes.

Effect of combined drink cans and steel fibers on the impact resistance and mechanical properties of concrete

2020 ◽  
Vol 14 (2) ◽  
pp. 6734-6742
Author(s):  
A. Syamsir ◽  
S. M. Mubin ◽  
N. M. Nor ◽  
V. Anggraini ◽  
S. Nagappan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Impact Resistance ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Indirect Tensile ◽  
The Impact

This study investigated the combine effect of 0.2 % drink cans and steel fibers with volume fractions of 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% to the mechanical properties and impact resistance of concrete. Hooked-end steel fiber with 30 mm and 0.75 mm length and diameter, respectively was selected for this study.  The drinks cans fiber were twisted manually in order to increase friction between fiber and concrete. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the strength performance of concrete, especially the compressive strength, flexural strength and indirect tensile strength. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the compressive strength, flexural strength and indirect tensile strength by 2.3, 7, and 2 times as compare to batch 1, respectively. Moreover, the impact resistance of fiber reinforced concrete has increase by 7 times as compared to non-fiber concretes. Moreover, the impact resistance of fiber reinforced concrete consistently gave better results as compared to non-fiber concretes. The fiber reinforced concrete turned more ductile as the dosage of fibers was increased and ductility started to decrease slightly after optimum fiber dosage was reached. It was found that concrete with combination of 2% steel and 0.2% drink cans fibers showed the highest compressive, split tensile, flexural as well as impact strength.    

scholarly journals Experimental Study on the Mechanical Properties and Compression Size Effect of Recycled Aggregate Concrete

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2323
Author(s):  
Yubing Du ◽  
Zhiqing Zhao ◽  
Qiang Xiao ◽  
Feiting Shi ◽  
Jianming Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Size Effect ◽  
Compressive Stress ◽  
Failure Modes ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Aggregate Concrete ◽  
Substitution Ratio ◽  
The Impact

To explore the basic mechanical properties and size effects of recycled aggregate concrete (RAC) with different substitution ratios of coarse recycled concrete aggregates (CRCAs) to replace natural coarse aggregates (NCA), the failure modes and mechanical parameters of RAC under different loading conditions including compression, splitting tensile resistance and direct shear were compared and analyzed. The conclusions drawn are as follows: the failure mechanisms of concrete with different substitution ratios of CRCAs are similar; with the increase in substitution ratio, the peak compressive stress and peak tensile stress of RAC decrease gradually, the splitting limit displacement decreases, and the splitting tensile modulus slightly increases; with the increase in the concrete cube’s side length, the peak compressive stress of RAC declines gradually, but the integrity after compression is gradually improved; and the increase in the substitution ratio of the recycled aggregate reduces the impact of the size effect on the peak compressive stress of RAC. Furthermore, an influence equation of the coupling effect of the substitution ratio and size effect on the peak compressive stress of RAC was quantitatively established. The research results are of great significance for the engineering application of RAC and the strength selection of RAC structure design.

scholarly journals Influence of layering pattern of modified kenaf fiber on thermomechanical properties of epoxy composites

2019 ◽  
Vol 36 (1) ◽  
pp. 47-62
Author(s):  
AR Mohammed ◽  
MS Nurul Atiqah ◽  
Deepu A Gopakumar ◽  
MR Fazita ◽  
Samsul Rizal ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Modification ◽  
Epoxy Matrix ◽  
Epoxy Composites ◽  
Woven Composites ◽  
Fiber Reinforced ◽  
Kenaf Fiber ◽  
Kenaf Fibers ◽  
The Impact ◽  
Woven Kenaf

Natural fiber-reinforced composites gained considerable interest in the scientific community due to their eco-friendly nature, cost-effective, and excellent mechanical properties. Here, we reported a chemical modification of kenaf fiber using propionic anhydride to enhance the compatibility with the epoxy matrix. The incorporation of the modified woven and nonwoven kenaf fibers into the epoxy matrix resulted in the improvement of the thermal and mechanical properties of the composite. The thermal stability of the epoxy composites was enhanced from 403°C to 677°C by incorporating modified woven kenaf fibers into the epoxy matrix. The modified and unmodified woven kenaf fiber-reinforced epoxy composites had a tensile strength of 64.11 and 58.82 MPa, respectively. The modified woven composites had highest flexural strength, which was 89.4 MPa, whereas, for unmodified composites, it was 86.8 MPa. The modified woven fiber-reinforced epoxy composites showed the highest value of flexural modulus, which was 6.0 GPa compared to unmodified woven composites (5.51 GPa). The impact strength of the epoxy composites was enhanced to 9.43 kJ m−2 by the incarnation of modified woven kenaf fibers into epoxy matrix. This study will be an effective platform to design the chemical modification strategy on natural fibers for enhancing the compatibility toward the hydrophobic polymer matrices.

Impact response of a low-cost randomly oriented fiber foam core sandwich panel

2018 ◽  
Vol 52 (25) ◽  
pp. 3429-3444 ◽  
Author(s):  
Ezequiel Buenrostro ◽  
Daniel Whisler
Keyword(s):  
Mechanical Properties ◽  
Sandwich Panel ◽  
Low Cost ◽  
Three Dimensional ◽  
Cost Effective ◽  
Foam Core ◽  
Fiber Reinforced ◽  
Manufacturing Method ◽  
Manufacturing Techniques ◽  
The Impact

Three-dimensional fiber-reinforced foam cores may have improved mechanical properties under specific strain rates and fiber volumes. But its performance as a core in a composite sandwich structure has not been fully investigated. This study explored different manufacturing techniques for the three-dimensional fiber-reinforced foam core using existing literature as a guideline to provide a proof of concept for a low-cost and easily repeatable method comprised of readily available materials. The mechanical properties of the fiber-reinforced foam were determined using a three-point bend test and compared to unreinforced polyurethane foam. The foam was then used in a sandwich panel and subjected to dynamic loading by means of a gas gun (103 s−1). High-strain impact tests validated previously published studies by showing, qualitatively and quantitatively, an 18–20% reduction in the maximum force experienced by the fiber-reinforced core and its ability to dissipate the impact force in the foam core sandwich panel. The results show potential for this cost-effective manufacturing method to produce an improved composite foam core sandwich panel for applications where high-velocity impacts are probable. This has the potential to reduce manufacturing and operating costs while improving performance.

Hybrid composite laminates reinforced with flax-basalt-glass woven fabrics for lightweight load bearing structures

2020 ◽  
pp. 152808372096074
Author(s):  
Mohamed A Attia ◽  
Marwa A Abd El-baky ◽  
Mostafa M Abdelhaleem ◽  
Mohamed A Hassan
Keyword(s):  
Mechanical Properties ◽  
Composite Laminates ◽  
Failure Modes ◽  
Woven Fabrics ◽  
Plane Shear ◽  
Load Bearing ◽  
Impact Properties ◽  
Basalt Glass ◽  
Interlaminar Shear ◽  
The Impact

An experimental investigation on the mechanical performance of interlayer hybrid flax-basalt-glass woven fabrics reinforced epoxy composite laminates has been performed. The tensile, flexural, in-plane shear, interlaminar shear, bearing, and impact properties of the fabricated laminates were investigated. Test specimens were fabricated using vacuum bagging process. Failure modes of all specimens were recorded and discussed. Results proved that the mechanical properties of flax-basalt-glass hybrid laminates are highly dominated by the reinforcement combinations and plies stacking sequence. Hybridizing flax fiber reinforced composite with basalt and/or glass fabrics provides an effective method for enhancing its tensile, flexural, in-plane shear, interlaminar shear, and bearing properties as well as controls the impact strength of the composite. The fabricated hybrids are found to have good specific mechanical properties benefits. Amongst the studied flax/basalt/glass hybrids, FBGs has the highest tensile properties, GBFs has the highest flexural and impact properties, and GFBs has the best shear and bearing properties. Flax-basalt-glass hybrid composites with different layering sequence seem to be an appropriate choice for lightweight load bearing structures.

scholarly journals Effect of Submicron Glass Fiber Modification on Mechanical Properties of Short Carbon Fiber Reinforced Polymer Composite with Different Fiber Length

2020 ◽  
Vol 4 (1) ◽  
pp. 5
Author(s):  
Nhan Thi Thanh Nguyen ◽  
Obunai Kiyotaka ◽  
Okubo Kazuya ◽  
Fujii Toru ◽  
Shibata Ou ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Glass Fiber ◽  
Fiber Length ◽  
Bending Strength ◽  
Mechanical Performance ◽  
Volume Fraction ◽  
Fiber Concentration ◽  
Static Tests ◽  
The Impact

In this research, three kinds of carbon fiber (CF) with lengths of 1, 3, and 25 mm were prepared for processing composite. The effect of submicron glass fiber addition (sGF) on mechanical properties of composites with different CF lengths was investigated and compared throughout static tests (i.e., bending, tensile, and impact), as well as the tension-tension fatigue test. The strengths of composites increased with the increase of CF length. However, there was a significant improvement when the fiber length changed from 1 to 3 mm. The mechanical performance of 3 and 25 mm was almost the same when having an equal volume fraction, except for the impact resistance. Comparing the static strengths when varying the sGF content, an improvement of bending strength was confirmed when sGF was added into 1 mm composite due to toughened matrix. However, when longer fiber was used and fiber concentration was high, mechanical properties of composite were almost dependent on the CF. Therefore, the modification effect of matrix due to sGF addition disappeared. In contrast to the static strengths, the fatigue durability of composites increased proportionally to the content of glass fiber in the matrix, regardless to CF length.

Experimental Investigation on the Dynamic Properties and Failure Mode of Carbon Fiber Reinforced Thermoplastic Composites

2014 ◽  
Vol 697 ◽  
pp. 102-108
Author(s):  
Jian Hua Ning
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Strain Rate ◽  
Failure Modes ◽  
Thermoplastic Composites ◽  
Elastic Model ◽  
Strength Increase ◽  
Fiber Reinforced ◽  
Carbon Fiber Reinforced ◽  
Constitute Model

Owing to the excellent mechanical properties and formability of carbon fiber reinforced thermoplastic composites, this composite has been applied in car industry. The static and dynamic mechanical properties of the composites are investigated under strain-rate from 0.001/s to 50/s. The experimental results show that the elastic model and tensile strength increase with the increase of strain rate, and show that the composite has remarkable rate-hardening effect. A constitute model that including rate-dependent effect is applied to present the strain-stress curve of the composite. The constitute model provides accurate constitute function for finite element analysis of the composite.. The microstructure of the composite is also investigated with scanning electric microscope, and the failure modes are discussed. The investigation provides the basis for engineering application of the composite.

scholarly journals Assessment of the Mechanical Properties of Sisal Fiber-Reinforced Silty Clay Using Triaxial Shear Tests

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Yankai Wu ◽  
Yanbin Li ◽  
Bin Niu
Keyword(s):  
Mechanical Properties ◽  
Failure Modes ◽  
Shear Fracture ◽  
Sisal Fiber ◽  
Dry Density ◽  
Silty Clay ◽  
Fiber Reinforced ◽  
Shear Tests ◽  
Maximum Dry Density ◽  
Sisal Fibers

Fiber reinforcement is widely used in construction engineering to improve the mechanical properties of soil because it increases the soil’s strength and improves the soil’s mechanical properties. However, the mechanical properties of fiber-reinforced soils remain controversial. The present study investigated the mechanical properties of silty clay reinforced with discrete, randomly distributed sisal fibers using triaxial shear tests. The sisal fibers were cut to different lengths, randomly mixed with silty clay in varying percentages, and compacted to the maximum dry density at the optimum moisture content. The results indicate that with a fiber length of 10 mm and content of 1.0%, sisal fiber-reinforced silty clay is 20% stronger than nonreinforced silty clay. The fiber-reinforced silty clay exhibited crack fracture and surface shear fracture failure modes, implying that sisal fiber is a good earth reinforcement material with potential applications in civil engineering, dam foundation, roadbed engineering, and ground treatment.

Study on Ramie Fiber Reinforced Polypropylene Composites (RF-PP) and its Mechanical Properties

2008 ◽  
Vol 41-42 ◽  
pp. 313-316 ◽  
Author(s):  
Li Ping He ◽  
Yong Tian ◽  
Lu Lin Wang
Keyword(s):  
Mechanical Properties ◽  
Fiber Length ◽  
Fiber Content ◽  
Ramie Fiber ◽  
Fiber Reinforced ◽  
Polypropylene Composites ◽  
Environmental Friendly ◽  
Pp Composites ◽  
Pre Treatment ◽  
The Impact

Natural fiber reinforced polypropylene composites (NF/PP) have attracted a lot of attention because of their light weight, good mechanical properties, recyclable and environmental friendly features. This work has successfully fabricated ramie fiber reinforced polypropylene composites (RF/PP) with a hybrid method of melt-blending and injection molding. Different RF/PP eco-materials have been fabricated by varying the fiber length, fiber content and way of fiber pre-treatment. This paper studied the mechanical properties of the fabricated RF/PP composites in depth by investigating the mechanical behaviors of RF/PP and microstructures of the ruptured surfaces. The results show that the increases of fiber length and fiber content can improve the tensile strength, flexural strength and compression strength apparently, but result in negative influences on the impact strength and elongation behaviors of RF/PP composites. The optimal addition amount of ramie fiber is around 20 wt%. The pre-treatment of ramie fiber in 10%~15% NaOH is good to the mechanical properties of RF/PP. The fiber length can be varied in the range of 3-8 mm. It is expected that the fabricated RF/PP composites can be applied to automobile industry as environmental friendly eco-materials.

Sign in / Sign up

Export Citation Format

Share Document