| Basalt fiber reinforced resin-composites have excellent properties such as environmentally friendly protection,low cost and wide application fields.In this thesis,two-dimensional braided composites were made with epoxy resin and unsaturated polyester resin reinforced by basalt filament.Grid structure materials were developed based on the studies on the composites property.Firstly,an accurate resin content control device,an auxiliary tensioning device and an abrasion-resistance testing device for heavy basalt engineering materials were developed.The relation between rotation speed y and working frequency x was studied and described as y=23.32x+104.16(5≤x≤50).When the device working time is set to 1 min,accurate resin weight depends on the device working frequency.Secondly,cords with different structures were braided.The tensile properties tests revealed that under the experiment conditions,the fracture strength of double-braided structure cord decreased with the increase of braid pitch in the outer layer.The fracture strength was 16.92 c N/tex when braid pitch was 30 mm,while it was 11.4 c N/tex when 60 mm.Number of core affects fracture strength considerably.When the inner part had 4cores,the fracture strength reached to 18.87 c N/tex,and it declined to 7.93 c N/tex when only 1 core left.Core braid pitch has some influence on fracture strength.The bigger core braid pitch,the higher fracture strength.The fracture strength was 12.7 c N/tex with braid pitch 20 mm,and it was 19.8 c N/tex with braid pitch 60 mm.When the outer part was the same,the fracture strength of double braid with parallel fiber was less than that of double braid,which was reduced by 14%.Four kinds of linear basalt fiber reinforced resin-composites with different fiber contents were prepared by using resin content control device.The mechanical properties of the composites were tested.The results showed that the bending strength and compressive strength of the composites decreased with the increase of resin content.When the resin content was 30%,the mechanical properties of the composites were the best.The mechanical properties of two-dimensional linear basalt fiber reinforced resin-composites were tested.The results showed that the bending strength of the composites decreases with the increase of the number of cores.The bending strength of the composites was 1 236 MPa when the number of core was 1,and it was 600 MPa when the core increased to 4.With the increase of braid pitch in the outer part,the fracture strength declined and the bending strength and compression strength rose.The fracture strength,bending strength and compression strength were 429 MPa,590 MPa,75 MPa respectively when braid pitch in outer part was 30 mm.They were 284 MPa,1 059 MPa and 131 MPa when braid pitch was 60 mm.The abrasion resistance became worse.The bending strength loss rate was 7.6% when braid pitch was 30 mm.The mass loss rate was only 1.25% when braid pitch was 40 mm.With the increase of core braid pitch,the fracture strength,bending strength and compression strength rose.When core braid pitch was 60 mm,the fracture strength,bending strength and compression strength was 555.97 MPa,1 666.18 MPa and 240.61 MPa respectively.Compared with double braid,the fracture strength and compressive strength of double braid with parallel fiber were reduced by 10.67% and 31.25%.The bending strength was increased by 12.22%.Finally,grid-structure materials were made by weaving and braiding.Tensile properties of the two kinds of grid were tested.The results showed that the tensile properties of leno weave were better than those of gause weave.Facture occurred at the knots of grid structure.Intersection of woven mesh fabric was easy to slip and the fabric was easy to deform,but fibers could reach to maximum extension.Yarns in braided grid were not easy to slip and the structure stability was good,but the yarns in the intersection point were easy to break. |
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