CHARACTERIZATION OF MECHANICAL PROPERTIES OF A 3D-PRINTED CONTINUOS BASALT FIBER-REINFORCED COMPOSITE
Topic(s) : Material science
Co-authors :
Marco ZANELLI (ITALY), Giulia RONCONI (ITALY), Valentina MAZZANTI (ITALY), Francesco MOLLICAAbstract :
Components obtained through Fused Filament Fabrication (FFF) usually have poor mechanical properties mostly because of the layering procedure that is used to fabricate objects. In order to solve this issue, a possibility that has been proposed in recent years is to use continuous reinforcing fibers, so that Continuous Fiber Reinforced Polymer Composites (CFRPC) are obtained and is well known that increasing fiber length can improve mechanical properties by a large extent.
In this work, a continuous basalt fiber reinforced composite was characterized in simple tension.
The matrix is an unreinforced polyamide 12 (PA12), while the reinforcement is a commercial continuous basalt fiber (CBF), both supplied by Anisoprint. To create the composite, the two are co-extruded together.
The printer used is an Anisoprint Composer A3 with two extruders, one for composite co-extrusion and one for printing standard thermoplastics.
A 5-wall outer shell is made by a PA12 reinforced with 10vol% of short carbon fibers (PA12-10%scf), to obtain a good print quality and dimensional accuracy.
The outer shell was taken into account during characterization, so that only the central portion made of CBF and unreinforced PA12 was characterized.
For both matrices and the composite, specimens are printed with line deposition and continuous fiber orientation of 0°, 90° and [45°/-45°]s and tested in tension according to ASTM D3039 and ASTM D3518.
Tensile experiments showed that the introduction of continuous fiber into the specimen significantly improved mechanical properties. As the deposition angle varies the changes in mechanical properties are not very pronounced, while for CBF-reinforced composite specimens anisotropy increases, both in stiffness and strength.
Recently, it has been shown that 3D-printed objects can be modeled as composite materials using Classical Lamination Theory (CLT), in which each 3D printed layer is represented as a unidirectional lamina.
The tension tests confirmed that CLT is able to describe the stiffness properties of all laminates accurately. Moreover, strength properties can be successfully predicted using this approach through the Tsai-Hill criterion for modeling the breakage of a single 3D-printed layer. From a quantitative point of view, the model tends to slightly overestimate the experimental results.
This is mainly due to the fact that with CLT, voids within the sample, adhesion between adjacent lines and between successive layers are neglected. All these factors are highly dependents on the deposition pattern and printing sequence.
In this work, a continuous basalt fiber reinforced composite was characterized in simple tension.
The matrix is an unreinforced polyamide 12 (PA12), while the reinforcement is a commercial continuous basalt fiber (CBF), both supplied by Anisoprint. To create the composite, the two are co-extruded together.
The printer used is an Anisoprint Composer A3 with two extruders, one for composite co-extrusion and one for printing standard thermoplastics.
A 5-wall outer shell is made by a PA12 reinforced with 10vol% of short carbon fibers (PA12-10%scf), to obtain a good print quality and dimensional accuracy.
The outer shell was taken into account during characterization, so that only the central portion made of CBF and unreinforced PA12 was characterized.
For both matrices and the composite, specimens are printed with line deposition and continuous fiber orientation of 0°, 90° and [45°/-45°]s and tested in tension according to ASTM D3039 and ASTM D3518.
Tensile experiments showed that the introduction of continuous fiber into the specimen significantly improved mechanical properties. As the deposition angle varies the changes in mechanical properties are not very pronounced, while for CBF-reinforced composite specimens anisotropy increases, both in stiffness and strength.
Recently, it has been shown that 3D-printed objects can be modeled as composite materials using Classical Lamination Theory (CLT), in which each 3D printed layer is represented as a unidirectional lamina.
The tension tests confirmed that CLT is able to describe the stiffness properties of all laminates accurately. Moreover, strength properties can be successfully predicted using this approach through the Tsai-Hill criterion for modeling the breakage of a single 3D-printed layer. From a quantitative point of view, the model tends to slightly overestimate the experimental results.
This is mainly due to the fact that with CLT, voids within the sample, adhesion between adjacent lines and between successive layers are neglected. All these factors are highly dependents on the deposition pattern and printing sequence.