Abstract
The reliability of engine block is of most importance.
In order to make research on the reliability of the block with time at the key part of Q475 engine block in the operation process, the author has done the transient dynamics analysis employing the Explicit FEM software ANSYS/LS-DYNA. This finite element model of the transient dynamics analysis was developed with 116800 nodes and 106570 elements. The element group consisted of solids, shells. The major output of the analysis included the stress, strain and deformation information in two engine operation cycles. The results revealed that the stress at the ambient of bolt hole of block and cylinder head is the most severe because of the bolt pretightening effect, whereas, the dynamic stress is not so severe. There is more harsh static stress at the mid part of the block, the less at the top part and it gradually decreases from the mid to the bottom. The dynamic stress is almost the same at the different part of the block, the most severe variation of dynamic stress occurs at the main bearing seat in relation to the other part of the block, and, the amplitude is the greatest, too. The dynamic stress play a most apparent role at the cylinder liner, and the peak value appears when the ignition begins. The vibration of whole block has the characteristics of the most severe along the axis orientation of cylinder, the less along the transverse and the least along the axis of crankshaft.