Mold

A method of adjusting a coefficient of thermal expansion of a member made of a fiber-reinforced resin, the method comprising:

• adjusting a coefficient of thermal expansion in a predetermined direction by increasing or decreasing a quantity of fiber having a grain direction in agreement with the predetermined direction,
• wherein the member is a plurality of partial surface dies which is included in a mold used when curing a cylindrical laminate obtained by laminating a prepreg, the mold comprising:
• a core die made of an invar alloy and located inside the laminate;
• and
• a surface die that is located outside the laminate and includes the plurality of partial surface dies,
• wherein the partial surface dies are arranged in a circumferential direction of the laminate so as to cover an entire circumferential surface of the laminate,
• wherein in the fiber-reinforced resin of each of the partial surface dies, a quantity of fiber having a grain direction in agreement with the circumferential direction differs from a quantity of fiber having a grain direction in agreement with an axial direction,
• wherein each of the partial surface dies is formed by laminating a textile material containing carbon fiber and a unidirectional material containing the carbon fiber,
• wherein a ratio of a quantity of (i) the carbon fiber having a grain direction in agreement with the axial direction within the textile material, (ii) the carbon fiber having a grain direction in agreement with the circumferential direction within the textile material, (iii) the carbon fiber having a grain direction in agreement with the circumferential direction within the unidirectional material and (iv) the carbon fiber having a grain direction in agreement with the axial direction within the unidirectional material is 1:1:2:0, and
• wherein each of the partial surface dies is constructed such that a coefficient of thermal expansion in the circumferential direction is smaller than a coefficient of thermal expansion in the axial direction and more closely approximates a coefficient of thermal expansion of the core die than the coefficient of thermal expansion in the axial direction.