Lightweight spar cap with concave structure for wind turbine blade and manufacturing method thereof, wind turbine blade and manufacturing method thereof

A lightweight wind turbine blade, comprising an upper shell (1), a lower shell (2), a web (5) and two lightweight spar caps for the wind turbine blade, wherein the lightweight spar caps for the wind turbine blade are concave spar caps, and the two concave spar caps comprise a pressure surface lightweight spar cap (3) and a suction surface lightweight spar cap (4):

• a longitudinal positioning structure is provided on one side of each of the pressure surface lightweight spar cap (3) and the suction surface lightweight spar cap (4);
• double ends of the web (5) are respectively connected with the positioning structures of the pressure surface lightweight spar cap (3) and the suction surface lightweight spar cap (4) through a positioning matching structure, and are fixedly connected with the pressure surface lightweight spar cap (3) and the suction surface lightweight spar cap (4) as a whole, to form a lightweight spar cap structure combination;
• and
• one end of the lightweight spar cap structure combination for the wind turbine blade is connected with the upper shell (1), and the other end thereof is connected with the lower shell (2);
• the lightweight spar cap structure combination for the wind turbine blade is fixedly connected with the upper shell (1) and the lower shell (2) as a whole;
• double ends of the upper shell (1) and the lower shell (2) are correspondingly connected to form a leading edge (6) and a trailing edge (7) respectively;
• the lightweight spar cap is groove-shaped as a whole, and comprises supporting portions (32) located on two wings of the lightweight spar cap and an intermediate connecting portion (36) connecting the two supporting portions (32);
• one splicing surface formed by connecting the supporting portion (32) and the intermediate connecting portion (36) is an integral plane;
• the shape of the integral plane is configured to be consistent with an inner side of an upper shell (1) or a lower shell (2) of the wind turbine blade for abutting;
• the other splicing surface formed by connecting the supporting portion (32) and the intermediate connecting portion (36) is a groove-shaped discontinuous plane;
• a positioning groove (34) formed by the groove-shaped discontinuous plane is configured to be consistent with an end of a web (5) of the wind turbine blade for abutting and nesting;
• and
• a cross section of the intermediate connecting portion (36) is in a trapezoidal shape;
• a reinforcing body of the intermediate connecting portion is formed by sequentially superimposing multiple layers of reinforcing fiber cloths from an upper base to a lower base of a trapezoid;
• a cross section of the reinforcing body formed by superimposing the reinforcing fiber cloths presents a trapezoidal shape,
• wherein the positioning groove is formed by the supporting portions and the intermediate connecting portion of the lightweight spar cap, and wherein a thickness of the supporting portion (32) is greater than that of the intermediate connecting portion (36), and each of the supporting portions wraps a lateral side and a part of a side of the intermediate connecting portion (36) into the positioning groove (34) that is inverted trapezoidal, the side is located at the other splicing surface formed by connecting the supporting portion (32) and the intermediate connecting portion (36).