PSI - Issue 5

Lucjan Witek et al. / Procedia Structural Integrity 5 (2017) 369–376 Lucjan Witek et al. / Structural Integrity Procedia 00 (2017) 000 – 000

372

4

Fig. 4. Tension plot of the specimen cut from the crankshaft.

Analysed crankshaft is made out of carbon steel 45. This steel (known as C45 according to EN) consists of 0.42 0.50 % of carbon and is commonly used in mechanical engineering (Multistal&Lohmann Corporation, 2017). In Table 1 the mechanical properties for the crankshaft material (based on results of tension test) are compared to the standard value for steel 45. As seen from this table, the ultimate tensile strength, yield stress and modulus of elasticity of crankshaft material are in the range defined by the standard (DIN EN 10083-2, 2017). The total elongation of crankshaft material (  = 20.6%) is only a bit larger than the standard value (14-17 %).

Table 1. Mechanical properties of crankshaft material and the standard value for steel 45. Properties Symbol Unit Crankshaft material (real value)

Steel 45 (according to standard), (2017 )

Ultimate tensile strength

UTS

MPa MPa GPa

758 480 207 20.6

560-850 275-490 198-207

Yield stress

YS

Young modulus Total elongation

E

%

14-17



4. Crankshaft model. Loads and boundary conditions The geometrical (3D) model of crankshaft was made using the Catia software. In next step the model was exported to the Abaqus program and divided onto finite elements. Crankshaft model (Fig. 5a) consists of 52640 nodes and 242298 tetragonal (TET-4) finite elements with linear shape function (Abaqus user’s manual, 2014) . In pin fillets the mesh was concentrated. In Fig. 5a are also seen segments of connecting rods, which transfers the loads from the piston onto crankshaft. The crankshaft material (steel 45) was defined as linear-elastic with the following properties: modulus of elasticity - 207 GPa, Poisson’s ratio - 0.3, density - 7800 kg/m 3 . a) b)

Fig. 5. (a) Numerical model of the crankshaft. Selected boundary condition (related to connection with the clutch) and load no 1 (from piston, after ignition in cylinder 1). (b) Selected boundary conditions: the bearing journals and contact on crank pin.