桨叶结构的设计[中文1880字] 【中英文WORD】

桨叶结构的设计[中文1880字] 【中英文WORD】,中文1880字,中英文WORD,桨叶结构的设计[中文1880字],【中英文WORD】,桨叶,结构,设计,中文,1880,中英文,WORD The Design Of The Lade Blade structure design of the main work is according to the overall design and aerodynamic design and the parameters of the helicopter, helicopter is designed to meet tactical technical requirements and overall technical requirements of blade structure. Blade structure design to meet the blade aerodynamic shape, rotor dynamics, fatigue and strength, reliability and maintainability, manufacturability and economy requirements, etc. Blade structure design of main work include: (1) The blade material design, select material determine blade materials system and variety. (2) The blade configuration design, determine the structure of the blade profile typical forms, joint form and main structure size. (3) Blade layer design and structure parameters are calculated. (4) The blade structure detail design. Blade of the main girder, skin structure, after a period of parts and connectors. In addition, there is blade tip cover, rear adjustment piece, front bag piece, balance weight, etc. Blade configurations by early wood blade, blade hybrid structure, the metal blade, metal and composite materials mixed blade structure and development of the whole composite blade, to date, most advanced helicopter blades with composite materials. Blade configuration is mainly according to the shape of the blade material and supporting as well as the joint form to differentiate, blade configuration design, want to consider domestic blade development and industry technical accumulation, the basis of reasonable selection of blade configurations. 1. The metal blade configurations Metal blades are usually made of girder, joint, in the back cover and the blade tip, trailing edge adjustment piece, front bag piece, such as balance weight zero components. According to the shape of the girder and the forming process is different, can be divided into the hollow extruded beam blade, C shape extruded beam blade, illustrated the paddle blade and a closed cavity composite beams. (1) Extrusion hollow beam Extrusion hollow girder according to blade design requirements, the girder extrusion into D beam, can be squeezed into trapezoidal beam. Usually the shape of the hollow beam by mechanical processing and become, form the front of the oar Ye Yi type. The configuration of the blade good torsional stiffness, beam can be individually under complex load of blade. Hollow beam are usually made of aluminium alloy extrusion forming, inner surface son what shape and surface quality of the girder by extrusion technology guarantee, usually inner surface and girder as the surface processing benchmark. Therefore, extruded beam inner cavity size and high surface quality requirement, manufacture process is difficult. (2) C shape extruded beam girder (C) C girder is generally made by aluminum alloy extrusion forming, surface after machining. C beam form at the front part of the airfoil, upper and lower surface constitute a part of the airfoil surface. C beam inner surface is open (concave), surface processing and quality inspection. Because C beam rear openings, low torsional rigidity of girder, often need to skin (or shape wall) or Ⅱ girder together constitute a single or double closed cavity closed load-carrying structure. (3) Illustrated the blade Illustrated by alloy steel or commonly qin alloy extrusion forming, cross section shape according to the requirements of blade overall configuration and the bearing can be round or oval. Steel of high strength, modulus, impact toughness is better, but better than strength, modulus and aluminum alloy. (4) Other forms More closed cavity composite beam is composed of steel plate bending forming C shape, D beam element, by welding or bonding of closed cavity load-carrying structure. Girder for stainless steel plate after forming glue connect together to form more closed cavity beam. 2. Composite blade configurations Composite blade configuration mainly based on the typical section girder structure, mainly including c girder single closed cavity, D beam double closed cavity structure with more closed cavity, etc. (1) C girder single closed cavity structure Is usually the most simple profile structure C shape beam single closed cavity structure, the structure is simple and good manufacturability. This configuration is similar to metal C shape beam structure, because it is open at the back of the C shape beam structure, section low torsional rigidity, for blade chord length is larger, after airfoil section area skin and bonding strength of filling material is the structure design of the difficulty, so this kind of configuration is usually suitable for medium and small helicopter blades. (2) D beam double closed cavity structure Single closed cavity structure stiffness and strength is relatively low, for blade chord length is larger, followed by regional skin and filler material knot strength to demand higher, can use double closed cavity structure. Double closed cavity D C beam girder structure is relatively single closed cavity structure is relatively complex, but this kind of structure can improve the torsional rigidity of blade and the blade trailing edge skin it strength. (3) closed cavity structure C beam and girder D configuration, essence is the metal blade configuration, only the metal blade hollow beam and solid beam with composite material instead. And more closed cavity structure, make full use of the composite materials can design, make the inside of the blade structure design, performance optimization, the stiffness, weight and strength characteristics better. More closed cavity girders of the blade is a kind of multi-channel structure of force transmission, due to more closed cavity structure, internal blade by hardwood, such as beam, Z girder,Ⅰ girder, Ⅱ girder, blade broken good security features. 3. The blade joint form Joint is the key component of blade connected to the propeller yi, blade root larger centrifugal force and under complex load are passed on from joint to oar yi. Blade joint depends primarily on connection with OARS yi in the form of form. Usually have a comb joint, flange and double winding bushing connecting forms, etc. (1) comb joint connection Comb joint connection generally adopts double ear or ears more connection, connection of the bolt hole, there are two of the same diameter, also have different sizes. Use comb connector, connector connected to the girders usually adopts bolt connection and bonding layer board, joint with girder web plate up and down the roots by bolt connection into a whole. Web thickness along the exhibition to become thinner, step by step implementation structure and strength design. (2) the flange connection Blade flange with OARS oar yi flange through a set of bolts connection, connection and girders connection bolt connection and bonding layer board, is often used to this kind of connection mode for more metal blades, straight type 8 main blade is made the connection form of the flange. (3) dual coil sleeve connection Blade roots of the two bushings through the bolt or pin connected to the propeller yi, this type of connection for composite blade, blade beam around the roots of bushing, joint is relatively simple. At present, the development of 9 straight, straight 11 composite blade is with double sleeve connection mode. 桨叶结构的设计 桨叶结构设计的主要工作是根据直升机总体设计和气动设计确定的参数，设计出满足战术技术要求和直升机总体技术要求的桨叶结构。桨叶结构设计要满足桨叶气动外形、旋翼动力学、疲劳与强度、可靠性与维修性、工艺性、经济性等要求。 桨叶结构设计主要工作包括: （1）桨叶的选材设计，确定桨叶所用材料体系和品种。 （2）桨叶的构型设计，确定桨叶典型剖面的构造形式、接头形式和主要结构尺寸。 （3）桨叶铺层设计和结构参数计算。 （4）桨叶结构细节设计。 桨叶的主要结构有大梁、蒙皮、后段件和接头。此外，还有桨尖罩、后缘调整片、前缘包片、平衡配重等。桨叶构型由早期的木质桨叶、混合式结构桨叶，向金属桨叶、金属和复合材料混杂结构桨叶和全复合材料桨叶发展，目前先进的直升机大多采用复合材料桨叶。桨叶的构型主要根据桨叶材料与大梁的形状以及接头形式来区分，进行桨叶构型设计时，要考虑国内桨叶研制的基础和行业的技术积累，合理选择桨叶的构型。 1.金属桨叶构型 金属桨叶通常由大梁、接头、后段件及桨尖罩、后缘调整片、前缘包片、平衡配重等零组件组成。根据大梁的形状和成形工艺不同，可分为空心挤压梁桨叶，C形挤压梁桨叶，管梁桨叶和多闭腔组合梁桨叶。 （1）空心挤压梁 空心挤压大梁可根据桨叶设计要求，将大梁挤压成D形梁，也可挤压成梯形梁。通常空心梁的外形经机械加工而成，构成桨叶翼型的前部。这种构型的桨叶抗扭刚度好，大梁可以单独承受桨叶的复杂载荷。空心梁通常由铝合金挤压成形，大梁内表面儿何形状与表面质量由挤压工艺保证，通常大梁内表面又作为外表面的加工基准。因此，挤压梁内腔尺寸和表面质量要求较高，工艺制造难度较大。 （2）C形挤压梁(C形梁) C形梁一般也是由铝合金挤压成形，表面经机械加工而成。C形梁构成翼型的前缘部分，上下表面构成部分翼型面。C形梁内表面(凹面)是开敞的，便于表面加工和质量检查。由于C形梁后缘开口，大梁的扭转刚度偏低，常需要与蒙皮(或外形壁板)或Ⅱ形梁一起构成单闭腔或双闭腔承力结构。 （3）管梁桨叶 管梁一般由合金钢或钦合金挤压成形，截面形状根据桨叶整体构型和承力的要求，可以是圆形或椭圆形。钢的强度高，模量、冲击韧性比较好，但比强度、比模量与铝合金不相上下。 （4）其他形式 多闭腔组合梁是由钢板折弯成形的C形、D形梁元件，通过焊接或胶接组成的多闭腔承力结构。大梁为不锈钢板弯曲成形后胶接在一起组成多闭腔梁。 2.复合材料桨叶构型 复合材料桨叶构型主要依据大梁典型剖面结构形式区分，主要包括c形梁单闭腔、D形梁双闭腔与多闭腔等结构形式。 （1）C形梁单闭腔结构 通常最简单的剖面构造是C形梁单闭腔结构，该结构简单，工艺性好。这种构型类似金属C形梁结构，由于采用后部开口的C形梁结构，剖面抗扭刚度低，对于弦长较大的桨叶，翼型后段区蒙皮与填充材料的胶接强度是这种结构的设计难点，所以这种构型通常适用于中、小型直升机的桨叶。 （2）D形梁双闭腔结构 单闭腔结构的刚度与强度相对较低，对于弦长较大的桨叶，其后段区域蒙皮和填充材料的就结强度要求较高，可采用双闭腔结构。双闭腔D形梁结构较单闭腔C形梁结构相对复杂，但这种结构能提高桨叶的扭转刚度和桨叶后缘蒙皮的就结强度。 （3）多闭腔结构 C形梁和D形梁构型，实质是金属桨叶的构型思路，只是将金属桨叶的空心梁和实心梁用复合材料代替。而多闭腔结构，充分利用了复合材料的可设计性，使桨叶内部的结构设计效能趋于优化，其刚度、重量和强度特性更优。多闭腔大梁的桨叶是一种多路传力结构，由于采取多闭腔结构，桨叶内部有加强梁，如Z形梁、Ⅰ形梁、Ⅱ形梁等，桨叶破损安全特性好。 3.桨叶接头形式 接头是桨叶与桨毅连接的关键构件，桨叶根部承受较大的离心力和复杂载荷都由接头传递给桨毅。桨叶接头的形式主要取决于与桨毅的连接形式。通常有梳形接头、法兰盘和双缠绕衬套连接形式等。 （1）梳形接头连接 梳形接头连接一般采用双耳或多耳连接，连接的螺栓孔，有两个相同直径的，也有大小不同的。采用梳形接头，接头与大梁的连接通常采用螺栓连接和层板胶接，接头上下腹板与大梁根部通过螺栓连接成一个整体。腹板的厚度沿展向逐级变薄，实现结构的等强度设计。 （2）法兰盘连接 桨叶法兰盘与桨毅的法兰盘通过一组螺栓螺帽连接，接头与大梁的连接常采用螺栓连接和层板胶接，这种连接方式多用于金属桨叶，直8型机主桨叶就是采用这种法兰盘的连接形式。 （3）双缠绕衬套连接 桨叶根部的两个衬套通过螺栓或插销与桨毅相连，这种连接形式多用于复合材料桨叶，桨叶大梁绕根部衬套缠绕，接头相对简单。目前我国研制的直9、直11复合材料桨叶都是采用双衬套的连接方式。 8