Main girder structure for improving flutter critical wind speed and design method thereof

The invention relates to a main beam structure for improving flutter critical wind speed, when only incoming flow of wind in one direction exists, the main beam structure comprises two first box beams, a second box beam and a plurality of first cross beams, the plurality of first cross beams are arranged at intervals, and the width of the first box beams is smaller than that of the second box beam so as to form an asymmetric separated box beam structure; when incoming flows of wind in two directions exist, the main beam structure further comprises a third box beam, a plurality of second cross beams and a plurality of third cross beams which are arranged between the first box beam and the second box beam at intervals. According to the main beam structure capable of improving the flutter critical wind speed, the first box beam and the second box beam are arranged to be of an asymmetric separated box beam structure, the gap is formed between the first box beam and the second box beam, the main beam structure can