The 1 stress that is based on smooth sectional hypothesis distributings the rule pursues 1 it is intensity a kind of the most extensive stress distributinging model is introduced in the design. Right now, stress is linear function, with rectangle sectional lever getting a turn for exemple. (2) pursues 1 rectangular and sectional component getting a turn stress distributinging rule 1.
2 reverse stress distributinging rule by what film is likened to gotten rectangular and sectional lever ( of 2) seeing a picture is with the shearing stress of edge Y direction exemple (the ratio K ′ to fixed A and B is 3) invariable. Graph 2 rectangular and sectional lever reverse stress distributinging rule 1.
Distributinging rule is the stress of round axis when plasticity of 3 considerations material plasticity area (3) seeing a picture sets stretch area to be located in A/3 center ministry, divide its periphery part to be plasticity area. (4) from type (2) , (3) , (4) can summarize a such law: Sectional on a bit more aleatoric stress can convey those who be the greatest stress and a function that concern with opposite coordinate only to accumulate, still can analyse many practical stress to distributing model, still get same pattern. Individual stress distributinging model shoulds not afore-mentioned rules, this kind of case is not article discussion. If introduce =x/a of ′ of opposite coordinate X, y ′ =y/a, the maximum that takes stress is [S] , this kind of rule but depict is S= [S] F(x ′ , y ′ ) (5) pursues a kind of stress distributinging rule of 3 round axes 2 sectional bear the weight of the general expression of force by type (5) is integral to completely sectional S attainable sectional bear the weight of 5 of force main volumes: Axial force N, cut force Q, circle X, the curved quadrature Mx of Y axis, my and torque Mn. type (5) specific writing also can be calculated of other direction bear the weight of force or its combination value. The analysis bears the weight of the expression of force, they have common function structure (4) seeing a picture. Function type is comprised by 3 paragraphs, the first paragraph can write down A α , to axial force and =2 of α shears force; To bending quadrature and torque α =3; The 2nd paragraph is the maximum of stress, reflect material performance, desirable for [S] ; The 3rd paragraph is the amount that concerns with sectional geometry appearance only. If express to bear the weight of with P force, the 3rd paragraph when express function with W, can draw up sectional bear the weight of the α of general expression P=a of force [S] W (6) pursues 4 sectional bear the weight of the sectional form that force analyses 3 module to alternate in designing law project, often be used and material are very finite, be like the Am of a value of reassign A, can decide what these circumstances fall to bear the weight of force (7) appoints material this kind, sectional appearance and the intensity computation model that A is worth call module. With type (6) is compared, introduce earmark, get (8) the basic formula that this is method of module commutation design, actually K is sectional relative scale. Because the amount of module is finite, list beforehand conditionally in hardware design the for future reference of fundamental strength condition of module, use formula next (design of the intensity of 8) forthright ground that finish. Of module bear the weight of force can be gotten with current now formula, but do not be confined to this, more meticulous analysis will is more economy, more reasonable design offers premise. Still imponderable case is at present complex to getting power, OK also build module by experiment or experience, in order to enlarge the limits of the design. Although of a series of module build should cost very great work, but this kind of labor is a kind of Yong Yi, avoided to design the repetition with much scope to work in fact. (When 1) design is sectional, first make choice of a kind of proper module, next by type (8) computation K is worth (9) all takes the measure with sectional module with K, round whole get can bearing of load P sectional. (2) school nucleus bears the weight of sectionally when force, find same material first, the module of same figure, calculate next K value, by type (8) bears the weight of sectionally certainly force. Sometimes [S] change along with sectional measure and change, by type (8) proves easily to want only in order to replace form (the K in 8) , module designs a law to still can be used. The intensity design of a spare parts may involve a few sectional, synthesize when group of a group of hardwares component and even overall when involve more sectional necessarily, but by type (8) is knowable, want to appoint the material of each spare parts only, sectional between the measure that keeps fixed is compared, each are sectional load has fixed function to concern to bear the weight of sectionally each force also has fixed concern necessarily, can design a kind many thereby sectional the module that waits for intensity combination, should calculate only when the design a control is sectional can decide all sectional, design workload will have more considerable decrease. Exemple: With module of test and verify of screw jack module commutation intensity devises a way. Screw material is A5 steel, nut material is cast-iron (5) seeing a picture. When example of 5 screw jacks is designed, the graph needs to be mixed by used data above all use requirement decides all sorts of intensity are allowable value, undertake helix next go up from interface of lock, whorl than pressing, the one department such as bending strength calculates shoulder of stage of bending strength of shear strength of whorl of stability of screw intensity, screw, nut, whorl, nut, but to giving module, afore-mentioned design computation correspondence are equivalent to following conditions: 1, 4.
05 ＜ 6.
84 for identity; From these the condition can conclude: ① these 7 conditions can simplify for the condition this one 2 conditions. ② design lifting capacity wants to press module dimension type only for the jack of Q (9) is multiplied with K=Q/17.
7 again round whole can. If ③ designs a kind of module, its dimension makes each condition takes identical cost mediumly, pass the comparison with module very easily to changing the jack after dimension scale to wash out the consideration that does not need. From this exemple intensity of commutation of visible application module designs a law to design a process how will simple. 4 last words alternate with module the law undertakes spare parts intensity designs OK and fast, accurate ground to solve a problem, a lot of designs that complete through much consideration ability work, with this kind of method the likelihood wants the operation with 9 simple paces to be able to be finished only. Formula of this kind of method is unified, easy control, although certain and mechanical model still is not clear about spare parts, should have module to still can be designed only reasonable and sectional. Here talked module commutation way with respect to the intensity problem of mechanical spare parts, in fact, this kind of method can apply at a lot of design domains, accordingly, the design method of this kind of new thinking has the applied perspective of wide spread. CNC Milling