attachment n. 1.附着,附着物;附属物,附件。 2.爱慕,依恋;依附 (for; to)。 3.【法律】逮捕;扣押(人,财产)。 4.扣押证。 attachments to a sewing machine 缝纫机的附件。 form a profound attachment for sb. 对某人大为倾倒。
tree n. 特里〔姓氏〕。 n. 1.树〔主要指乔木,也可指较大的灌木〕。 ★玫瑰可以称为 bush, 也可以称为 tree. 2.木料,木材;木构件;〔古语〕绞首台;〔the tree〕(钉死耶稣的)十字架;鞋楦。 3.树形(物),世系图,家系 (=family tree);【数学】树(形);【化学】树状晶体。 a banana tree 香蕉树。 an axle-tree 心棒,轴料。 a boot-tree 靴楦[型]。 a saddle-tree 鞍架。 at the top of the tree 在最高地位。 tree of Buddha 菩提树。 tree of heaven 臭椿。 tree of knowledge (of good and evil) 【圣经】知道善恶的树,智慧之树。 tree of life 生命之树,生命力的源泉【植物;植物学】金钟柏。 up a tree 〔口语〕进退两难,不知所措。 vt. 赶(猎兽等)上树躲避;〔口语〕使处于困境;穷追;把鞋型插入(鞋内)。
Different vibration characteristics between the two models are discussed . geometry mismatch in a turbine blade root , which arose in manufacturing process or caused by wearing out during service , leads to contact conditions changed in fir - tree attachments 汽轮机叶根制造尺寸误差或运行磨损造成的尺寸改变会导致叶根与轮盘接触状态变化,进而引起叶片固有频率发生漂移,并有可能接近共振频率而导致叶片事故。
As a result , shifting of the fundamental frequencies and redistribution of stress in the blade base possibly cause failure of the blade . a three - dimensional finite element model of a blade and its fir - tree attachments have been constructed and analyzed with taking into account of contact nonlinearity in the attachments and large deformation effect of the blade . the geometry mismatch was introduced into the finite element model by defining gaps between two contact surfaces in the attachments 分析结果表明叶根误差发生的位置对叶片弯曲振型的固有频率影响较大,对扭转振型影响较小;误差的大小对叶片各阶固有频率影响均较小,但对叶根应力分布有影响;比较发现,在计算固有频率时,将叶片在叶根处简单地处理成固支位移边界是不合理的。