Chopped Fiber Mat Research Articles

Analysis on the impact of recycled ceramic waste, fiber format, and manufacturing techniques on polymer composite properties

Dumping of construction waste is a growing issue in current situation and recycling and reusing are the suitable solutions for solving it. This effort aims to recycle and reuse of ceramic construction waste. This work examines the effects of inclusion of waste tile powder, change in the glass fiber form which was used as a reinforcement, and method of manufacturing method the polymer composite on the properties of the composite. Normal glass-reinforced polymer composites have good tensile, flexural, and toughness properties. The three forms of glass fibers used for the study includes, chopped fiber mat, glass fiber mesh, and woven glass fiber. Fillers are added to improve hardness and tribology related attributes. Composite fabrication was carried out by conventional hand layup, room temperature compression molding, and hot compression molding process. The goal is to harden the composite without reducing the tensile strength of the composite. ASTM D3039, ASTM D2240, and ASTM D570–98 procedures were adapted for measuring tensile, hardness and water intake properties respectively. Characterization was done through SEM image analysis. A result of 160.21 MPa tensile strength, Shore D hardness value of 96.7, and water absorption of 0.71 percent after 24 h of testing was recorded. Adding waste tile powder to the polymer composite increases its hardness and reduces surface defects without affecting tensile properties. Fiber form and manufacturing method also affect the output to some extent. The effect of water absorption on the hardness property of the composite was checked and found to be negligible which makes it durable and reliable to be used in moist environments. This composite can be used in automotive parts, moist environment, window and door frames, and in electrical panels.

Silicone polymer composites for thermal protection system: fiber reinforcements and microstructures

A new class of silicone polymer matrix composites was evaluated using a simulated solid rocket motor test apparatus. Conversion of this organic silicone polymer to a ceramic (i.e. silica) structure on exposure to flame impingement or high temperature, accounts for its outstanding thermal stability. A research program was aimed to develop and evaluate this new class of thermal protection materials for military applications. This article presents the effects of the type and form of reinforcements on the thermal performance of a novel class of silicone polymer matrix composites. Reinforcement types such as glass, silica, quartz, NextelTM, and NicalonTM were used. Reinforcement forms such as random continuous-fiber mat, chopped-fiber mat, 2-D fabric, 3-D fabric, chopped roving, and broadgood tapes with different ply angles were tested. Detailed microstructural, mass loss, and peak erosion analyses were conducted on the phenolic-based matrix composite (control) and silicone-based matrix composites to understand their protective mechanisms.

Two-body abrasive behaviour of untreated SC and R-G fibres polyester composites

In this paper, studies have been conducted to investigate the abrasive behaviour of chopped untreated sugarcane fibre (C-SCRP), unidirectional sugarcane fibre (UM-SCRP), and chopped strand mat of glass fibre (CSM-GRP)-reinforced polyester composites (in two different orientations, APO and PO). The effects of chopped fibre length (1, 5, and 10 mm) in C-SCRP, orientation of long fibre mat in UM-SCRP, and orientation of chopped fibre mat in CMS-GRP composites have been determined using SiC of 400 grit size abrasive paper under various loads and sliding velocities. Experimental results revealed that wear resistance of C-SCRP composite, tends to increase with increasing fibre length at lower load by about 44–75% and at higher load by about 17–50% while friction coefficient (0.35–0.1) showed no much dependence on fibre length and decreased significantly with increasing load and fluctuate with increasing speed. UM-SCRP composite gave wear resistance about two times higher than C-SCRP composite due to the fact that long fibres in UM-SCRP composite were well embedded in the matrix and subjected to the abrasion process only at their ends which required high energy to facilitate failure in the sugarcane fibres (SCFs). Beside that UM-SCRP composite with APO, consistently showed higher wear resistance compared to composite with PO and friction coefficient of similar trends and values as those observed for C-SCRP composite. SEM studies of the worn surfaces indicated that in C-SCRP composite wear mechanism dominated by material removal due to excessive deterioration in both fibre and matrix. While UM-SCRP composite showed less extent of fibre and matrix damage compared to C-SCRP and CSM-GRP composites. Comparison between SCRP and GRP composites revealed that wear resistance of CSM-GRP composite was about 2–3 times greater than UM-SCRP composite and 3–5 times greater than C-SCRP composite suggesting that the ranking order of the three composites tested according to the wear resistance is CSM-GRP ( W R APO > W R PO ) ≫ UM-SCRP ( W R APO > W R PO ) ≫ C-SCRP ( W R 5 mm ≫ W R 10 mm > W R 1 mm ) .

A Strain-Based Formulation for the Coupled Viscoelastic/Damage Behavior

A strain-based thermodynamics framework is proposed for modeling the continuum damage behavior of viscoelastic materials. Damage is represented by an internal state variable in the form of a symmetric second rank tensor. The effect of damage on the constitutive behavior is introduced through direct coupling between the damage variable and the viscoelastic internal state variables. This approach accounts for time-dependent damage as well as damage-induced changes in material symmetry. Also, damage evolution is modeled by employing the concept of damage surfaces. This work is motivated by experimental observations of the response of swirl-mat and random chopped fiber mat polymeric composites where viscoelastic creep was accompanied by a multitude of fiber/matrix interfacial cracks.