Fiber structure and fiber-reinforced composite

Abstract

A fiber structure, used as a reinforcement base material of a fiber-reinforced composite and including a multi-layered fabric including a warp layer and a weft layer, includes a first portion, and a second portion continuous with the first portion along one direction where the one direction refers to a direction in which warp yarns or weft yarns are adjacent to each other in the warp layer or the weft layer respectively. The warp yarns forming the second portion are thicker than those forming the first portion, and/or the weft yarns forming the second portion are thicker than those forming the first portion. When a pitch between the yarns refers to a distance between main axes of the yarns adjacent to each other in the one direction, the pitch between the yarns in the second portion is smaller than that in the first portion.

1 . A fiber structure used as a reinforcement base material of a fiber-reinforced composite, the fiber structure comprising:
 a multi-layered fabric including a warp layer and a weft layer, wherein   when one direction refers to a direction in which warp yarns are adjacent to each other in the warp layer or weft yarns are adjacent to each other in the weft layer,   the fiber structure comprises a first portion and a second portion, the first portion and the second portion being continuous with each other along the one direction,   each of the warp yarns forming the second portion is thicker than each of the warp yarns forming the first portion, and/or   each of the weft yarns forming the second portion is thicker than each of the weft yarns forming the first portion, and   when a pitch between the yarns refers to a distance between main axes of the yarns adjacent to each other in the one direction, the pitch between the yarns in the second portion is smaller than the pitch between the yarns in the first portion.   
     
     
         2 . The fiber structure according to  claim 1 , wherein
 fiber layers stacked in a thickness direction of the multi-layered fabric are bound together by a binder yarn in the thickness direction, and   when a distance between portions of the binder yarn refers to the distance between the portions, of the binder yarn, adjacent to each other in the one direction within a range of a thickness of the multi-layered fabric, the distance between the portions of the binder yarn in the second portion is different from the distance between the portions of the binder yarn in the first portion.   
     
     
         3 . The fiber structure according to  claim 1 , wherein
 a cross-sectional shape of a yarn in the first portion is different from a cross-sectional shape of a yarn in the second portion.   
     
     
         4 . The fiber structure according to  claim 1 , wherein
 a yarn density in the first portion is different from a yarn density in the second portion.   
     
     
         5 . A fiber-reinforced composite comprising a reinforcement base material formed of a fiber structure with a matrix resin impregnated into, wherein the fiber structure is the fiber structure according to  claim 1 .