Research on the effect of yield strength of circular saw blade on roll tensioning process

In this paper, a 2-D and 3-D finite element model of roll tensioning process of woodworking saw blade were established by Static/General module of ABAQUS software based on finite element method. The rolling force and tensioning stress distribution of circular saw blade were calculated by these two models which were proved to be true and reliable. The effects of yield strength of circular saw blade on tensioning stress distribution and rolling force were studied. The research achievements showed that a circular saw blade made with high yield strength obtained a higher tangential compressive stress and radial compressive stress in the rolled region during roll tensioning process, which has both advantages and disadvantages for the stability of the saw blade. Besides, a circular saw blade made with high yield strength also put forward higher requirements for roll tensioning equipment because of the large rolling force during roll tensioning process.

Circular saw blade is an important tool and is widely used in wood industry. Its stability, cutting precision, and material-saving ability are the most important features, especially for wood processing industry because of the shortage of precious wood. The Chinese government strongly supports the improvement of timber utilization. Therefore, TCT saw blade for wood is becoming thinner and thinner currently for reducing kerf loss and improving the utilization of materials.In step 1, the roll moved slowly down and elastic–plastic deformation was produced to the metal cutting saw blade. In step 2, the roll slowly raised and the saw blade was no longer under any load. The residual stress of saw blade was the tensioning stress.vThe three-dimensional 8 node reduced integral element C3D8R was chosen for the rolling ring of circular saw blade for metal and the 4-node general-purpose reduced integral shell S4R was chosen for the medial and lateral regions, which can reduce the number of elements to the maximum extent and improve the computational efficiency. The three parts were tied together through the way of shell-to-solid coupling. The number of elements was increased within the contact area between the circular saw blade and the roll for improving the accuracy of calculation, as shown in Fig. 3. The other parameters of the 3-D FEM model were the same as the 2-D model.

As shown in Fig. 8, rolling force was increased linearly with yield strength of circular saw blade when dent depth of rolled region is 10 μm because plastic deformation resistance was increased with yield strength. When yield strength of circular saw blade was 1200 MPa, the rolling force had reached to 19.2 kN. The substantial increase in rolling force brought challenges to the roll tensioning equipment of cermet saw blade.