求翻译：梁式机翼的桁条,一般都用薄铝板制成,他有开口和闭口两种.开口截面桁条的稳定性很差,而且由于壁很薄,实际上不能参与承受机翼的弯矩.闭口截面的桁条,稳定性较好,可以参与承受机翼的弯矩.但是这种桁条与蒙皮铆接时,有两道铆缝,对保持机翼表面光滑不利.是什么意思？

Beam type wing of truss section, General are with thin aluminum plate made, he has opening and closed two species. opening section truss section of stability is difference, and due to wall is thin, actually cannot participation bear wing of bending moments. closed section of truss section, stability

The beam plate wing purlin, all uses the thin aluminum sheet to make generally, he has the aperture and the blind tuyere two kinds. The open cross section purlin stability is very bad, moreover because the wall is very thin, in fact cannot participate in the withstanding wing the bending moment. The

Beam type wing of truss section, General are with thin aluminum plate made, he has opening and closed two species. opening section truss section of stability is difference, and due to wall is thin, actually cannot participation bear wing of bending moments. closed section of truss section, stability