attachment n. 1.附著,附著物;附屬物,附件。 2.愛慕,依戀;依附 (for; to)。 3.【法律】逮捕;扣押(人,財產(chǎn))。 4.扣押證。 attachments to a sewing machine 縫紉機的附件。 form a profound attachment for sb. 對某人大為傾倒。
tree n. 特里〔姓氏〕。 n. 1.樹〔主要指喬木,也可指較大的灌木〕。 ★玫瑰可以稱為 bush, 也可以稱為 tree. 2.木料,木材;木構(gòu)件;〔古語〕絞首臺;〔the tree〕(釘死耶穌的)十字架;鞋楦。 3.樹形(物),世系圖,家系 (=family tree);【數(shù)學(xué)】樹(形);【化學(xué)】樹狀晶體。 a banana tree 香蕉樹。 an axle-tree 心棒,軸料。 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 菩提樹。 tree of heaven 臭椿。 tree of knowledge (of good and evil) 【圣經(jīng)】知道善惡的樹,智慧之樹。 tree of life 生命之樹,生命力的源泉【植物;植物學(xué)】金鐘柏。 up a tree 〔口語〕進退兩難,不知所措。 vt. 趕(獵獸等)上樹躲避;〔口語〕使處于困境;窮追;把鞋型插入(鞋內(nèi))。
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 汽輪機葉根制造尺寸誤差或運行磨損造成的尺寸改變會導(dǎo)致葉根與輪盤接觸狀態(tài)變化,進而引起葉片固有頻率發(fā)生漂移,并有可能接近共振頻率而導(dǎo)致葉片事故。
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 分析結(jié)果表明葉根誤差發(fā)生的位置對葉片彎曲振型的固有頻率影響較大,對扭轉(zhuǎn)振型影響較小;誤差的大小對葉片各階固有頻率影響均較小,但對葉根應(yīng)力分布有影響;比較發(fā)現(xiàn),在計算固有頻率時,將葉片在葉根處簡單地處理成固支位移邊界是不合理的。