Connecting rod is finite yuan of analysis

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Foreword connecting rod is a car dynamic is delivered in engine important part, its sharp movement change the piston is the whirligig of crankshaft and intention the force on the piston expresses crankshaft in order to output power. Connecting rod should bear in working process assemble load (include plain bearing liner to be filled with too reach bolt to tighten force beforehand) and hand in change work to make load (include gas to erupt pressure and force) action, working requirement is more slashing. Contemporary car sides with environmental protection the development of energy-saving direction, requirement engine connecting rod is on the foundation of contented intensity and stiffness, should have measure the characteristic with small, light weight. Article application ABAQUS is finite yuan of software, undertook the school nucleus of intensity and stiffness to the some type connecting rod of new design. 1, of connecting rod three-dimensional and finite the three-dimensional geometry model of yuan of model connecting rod comes from CAD software PRO/E, use MSC/PATRAN to build finite yuan of model, use ABAQUS to undertake mechanical computation is analysed. The part that this computation includes has: Journal of connecting rod of nut of bolt of lid of connecting rod, connecting rod, connecting rod, connecting rod, piston pin, crankshaft, connecting rod is big plain bearing liner. The hexahedral unit that selects maneuver to consider precision taller differentiates reseau, divide in all for 24204 node, 17258 unit. Graph 1 for finite yuan of model. Graph 1 connecting rod is finite yuan of model is actual in the process, because be below the tie that bigger bolt tightens force beforehand, connecting rod and connecting rod lid all are in osculatory condition in whole analysis process, because undertook simplifying to the model here, it is connecting rod and connecting rod lid in the concrete analysis that build a model close for an organic whole, and do not affect final result. Same, bolt connecting rod and connecting rod nut also close for an organic whole. When building two axes model, the radius that this computation takes large shaft and small axis is less than radius of corresponding plain bearing liner respectively 0.

35mm and 0.

30mm. The plain bearing liner in considering actual project has been in be filled with after be out of shape although radius decrescent but still can't countershaft generation assembles stress, afore-mentioned model dimension can avoid what stress assembles between axis and plain bearing liner to appear. 2, software of computational process ABAQUS is current world on relatively general nonlinear computation analyses software. What basically involve in this computation is nonlinear the process basically includes bolt to pass closely with plain bearing liner beforehand be filled with. ABAQUS uses computational situation in computational analysis (Step) concept, computation basically is divided by operating condition process for 4 main measure. 2.

1 bring to bear on bolt tightens force beforehand above all, connect in each bolt head, nut and connecting rod lid, connecting rod touched place defines a contact to be opposite; Tighten offerred model beforehand for imitate bolt through ABAQUS technical secondary school (*Pre-tension Section) one is built to tighten a face beforehand in every bolt; The reference point that is in every to tighten scale model beforehand finally brings to bear on of 55kn tighten force tie beforehand. 2.

2 plain bearing liner are filled with too above all, in plain bearing liner and connecting rod (or connecting rod is built) the local definition contact that contacts is right; Define dimension interference through *Clearance (note: Value value is filled with too to lose a delegate, representing gap) . 2.

3~2.

4 bring to bear on respectively force (tensile) it is with explosive pressure load in these two processes, force brings to bear on to go up in connecting rod through small axis, and tie demarcate is on large shaft. Because there is clearance between axis and plain bearing liner, there can be the moment that produces free rigid body move in this one process accordingly, this is in finite yuan the meeting in static force analysis brings about computation not convergent and cannot undertake. Settlement method is introduce bedspring tie respectively on small axis and connecting rod, want to choose lesser bedspring stiffness coefficient only, can limit movement of free rigid body already, won't make final result produces big error again. 3, computational result and analysis 3.

Stress of 1 connecting rod and fatigue safety factor because connecting rod is to be being handed in change the job below load, use the following formula to calculate its fatigue safety factor: Graph 2 connecting rod are being assembled with the stress below drawing load action stress of distributinging connecting rod sees a picture 2, 3. The minorrest fatigue safety factor sees a table 2. Graph 3 connecting rod are being assembled erupt with gas body of lever of distributinging lever of the stress below pressure load action and the intermediate zone that connecting rod mains aspects 2.

The intermediate zone of small end of body of lever of 1 connecting rod and connecting rod 2.

The intermediate zone near body of lever of 3 connecting rod and bolt head 2.

The intermediate zone near body of lever of 3 connecting rod and nut 2.

The oily aperture of small end of 3 connecting rod 2.

5 3.

Big head of body of lever of 2 connecting rod and the osculatory pressure that connecting rod lid joins office pursue 4 assembling leave body of connecting rod lever with drawing load action the osculatory pressure that big head and connecting rod lid join office pursues 4 for lever of connecting rod of the first kind of plan body, the graph is body of lever of connecting rod of the first kind of 5 plan and connecting rod lid to combine a face to lie assemble load + the standard that reduces load to fall distributings to stress, the gules area in the graph expresses to lose a contact. Graph 5 assembling the osculatory pressure that erupts to join office body of lever of the connecting rod below pressure load action is large with connecting rod lid with gas to be able to see from the graph, connecting rod plain bearing liner and contact of connecting rod macrocephalic press muscularity part area to be more than 100Mpa. So, in connecting rod working load falls, big head of connecting rod plain bearing liner and connecting rod won't be detached. Graph 6 assembling load for connecting rod plain bearing liner and connecting rod are big + below drawing load press stress distributinging plan 6 assembling load for connecting rod plain bearing liner and connecting rod are big + below drawing load press stress distributinging plan 4, the connecting rod that conclusion 1) uses 42CrMoA to design, can satisfy its to design operating mode. 2) falls in load of connecting rod work, the standard that body of connecting rod lever and scale of union of connecting rod lid issue at all work load basically is more than 0Mpa to stress, won't detached. Aperture of main aspects of 3) connecting rod is in be out of shape inside limit. CNC Milling CNC Machining