Comparison between bearing strengths of molded-in and machined holes of GFR/PP composites

Osama, M. M.; Selmy, A.I.; Abdelhaleem, Ayman M. M.; Megahed, A. A.

doi:10.1038/s41598-022-18943-w

Cited by 5 publications

(3 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…They reported that, when FFSL increases, both L n and L w increase for FFSL up to 9 mm, while for FFSL more than 9 mm both L n and L w decrease. More details including histograms for each weight fraction and FFSL was provided in previous study 43 . Throughout this work, based on the above results, FFSL of 12 mm and 24 mm will be referred to as "long fiber/Polypropylene (LFRPP)" and "short fiber/ Polypropylene (SFRPP)", respectively.…”

Section: Resultsmentioning

confidence: 99%

Study of bearing strength for injection molded GFRPP composites under dry and wet conditions

Megahed

Osama

Selmy

et al. 2022

Sci Rep

View full text Add to dashboard Cite

Thermoplastics and fiber-reinforced thermoplastics represent great deals in nowadays industries and applications where some of these applications are projected to wet environment. The present study investigates the effect of water moisture on the bearing strength (BS) of Polypropylene (PP) and glass fiber (GF) reinforced Polypropylene (GFRPP) composites. PP and GFRPP are produced by injection molding using different GF weight fractions (wt%), 10, 20, and 30 wt%, and two different initial fiber lengths 12 and 24 mm. A burnout test indicated that produced specimens with 12 mm long fibers have higher final fiber lengths than those made of 24 mm long fibers. More water was absorbed for higher GF weight fractions. The results of the dry bearing test showed higher bearing strengths for specimens with higher GF wt% and longer fibers. The same observation was obtained from wet tests, while, wet-tested specimens of all compositions have higher strengths than their dry counterparts. Strain-at-break seemed to be significantly reduced by water absorption for all specimens. Specimens tested in wet conditions have different fracture morphology than dry ones due to the change in the mechanical behavior of the materials after water immersion.

show abstract

Section: Resultsmentioning

confidence: 99%

Study of bearing strength for injection molded GFRPP composites under dry and wet conditions

Megahed

Osama

Selmy

et al. 2022

Sci Rep

View full text Add to dashboard Cite

show abstract

“…More details including histograms of the fiber lengths were discussed in a previous study. 57 Throughout this work, based on the above results, FFSL of 12 mm and 24 mm will be referred to as "Long Fiber Reinforced Polypropylene (LFRPP)" and "Short Fiber Reinforced Polypropylene (SFRPP)," respectively.…”

Section: Actual Weight Fractionsmentioning

confidence: 99%

In-plane shear and tensile behavior of two-pass injection-molded glass fiber reinforced polypropylene composites with different fiber lengths

Osama

Selmy

Abdelhaleem

et al. 2022

Journal of Composite Materials

View full text Add to dashboard Cite

Glass fiber reinforced polypropylene (GF-PP) composites have proven a great potential in the designation and manufacturing of control arms, leaf springs, barriers, beams and bridge decks. Two-pass injection molding of GF-PP was investigated in this study. Polypropylene (PP) was injected with different weight fractions (w%) of chopped glass fibers (GFs) with different fiber feedstock lengths (FFSLs). The composites were then crushed and re-injected once again. Some specimens were burned out to check the actual weight fractions and fiber lengths after the injection processes. The fiber lengths dramatically decreased due to damages during two-pass injection processes and crushing. The manufactured specimens were tested in tension, and the results indicated that the tensile strength increased slightly at w = 10% of GF. Further increase of GF weight fraction leads to a drop in the tensile strength below neat PP. The results of SEM micrographs showed an increase in air voids concentrations at high GF percentages which clarifies the reason behind the drop in the tensile strength. Also, in-plane shear tests were carried out using the Iosipescu fixture where a slight increase in the in-plane shear strength was noticed by increasing fiber weight fractions. In-plane shear moduli of all specimens were measured experimentally by strain gauges and calculated theoretically. The shear modulus was enhanced by glass fiber addition and a further increase was noticed by increasing the fiber weight fractions.

show abstract

“…Glass fiber reinforced polymer matrix (GFRP) composites laminates are widely used in the aerospace, automotive, and marine industries, where drilling is typically required for subsequent component assembly. 1 However, drilling GFRP laminates typically results in burrs, splintering, and microcracks inside the GFRP structure in addition to delamination, fiber pull-out, and thermal degradation of the polymer matrix. [2][3][4][5] Additionally, the continuity of the fibers is lost as the GFRP in the hole region is being cut out, causing a significant stress concentration due to metallic inserts.…”

Section: Introductionmentioning

confidence: 99%

Experimental and numerical analysis of drilled‐ and molded‐hole glass fiber reinforced polymer matrix (GFRP) composites

Cengiz,

Öztürk,

Sabah

et al. 2024

Polymer Composites

View full text Add to dashboard Cite

Drilling glass fiber reinforced polymer matrix (GFRP) composites typically causes burrs, splintering, and microcracks within the GFRP structure, as well as delamination, fiber pull‐out, and thermal degradation of the polymer matrix. Designing and manufacturing molded‐hole GFRP components, as opposed to drilling, has recently been proposed as a promising method for overcoming the issues associated with drilling, for which there is limited research. Specifically, the mechanical response of molded‐hole GFRP has not been fully addressed in the literature. In the present study, molded and drilled GFRP composites with epoxy matrix were fabricated by hand lay‐up, and then the samples were analyzed utilizing experimental and numerical analysis techniques. Stress and strain analyses of GFRP samples were performed in Ansys Transient Structural Analysis. Although the fiber orientations of the layer geometries [0°/90°] and 3D models were the same, an additional layer was defined in the direction of the fiber orientation [45°/−45°] of molded‐hole composites to simulate the fiber accumulation effect. Experimental findings revealed that the flexural strength of molded composites was 12% greater than that of drilled composites. According to the numerical analysis, 98.7% proximity was achieved between the experimental and numerical results. Thus, the present study has provided numerical modeling to understand the flexural strength of molded composites for the first time, which will contribute to the increased use of molded composites in numerous applications in the fields of aerospace, automotive, and marine.Highlights Drilled‐ and molded‐hole GFRP composites were produced by hand lay‐up. Flexural properties of the composites were examined via 4P bending tests. Flexural strength of molded composites was higher than that of drilled ones. 98.7% proximity was achieved between the experimental and FEM results. A unified FEM method is proposed for the molded‐hole composites.

show abstract

Comparison between bearing strengths of molded-in and machined holes of GFR/PP composites

Cited by 5 publications

References 58 publications

Study of bearing strength for injection molded GFRPP composites under dry and wet conditions

Study of bearing strength for injection molded GFRPP composites under dry and wet conditions

In-plane shear and tensile behavior of two-pass injection-molded glass fiber reinforced polypropylene composites with different fiber lengths

Experimental and numerical analysis of drilled‐ and molded‐hole glass fiber reinforced polymer matrix (GFRP) composites

Contact Info

Product

Resources

About