finite element method

Tractor operators get exposed in a wide range of vibrations, so that they lead to discomfort and long term or permanent disorders. One solution for this problem is decreasing transmitted vibration to the driver by selecting a suitable seat cushion. Therefore, an ergonomic seat cushion was designed for Iranian operators especially and compared with the available seat. Both of seat cushions were analyzed in the frequency range of 3 to 66 Hz in four excited vibrations of 5.0, 1, 5.1 and 2 m/s2 for three groups of drivers with masses of 55, 70 and 85 kg by using finite element method. The results of this study showed that the ergonomic seatpan cushion can provide more comfort and convenience for the driver in excited vibrations range and this seat cushion can be a suitable alternative to the available seat-pan cushion. However, the investigation of the output vibration magnitude on the seat backrest regions showed that the available seat backrest provides more comfort and convenience for the driver in comparison with the ergonomic seat cushion. Therefore, the combination of the ergonomic seat-pan cushion and the available seat backrest can improve the efficiency of the available seat cushion of the tractor to reduce transmitted vibrations to the driver.

In this study, distribution and tension concentration are analyzed in dowel joint. In current research, the effect of screw diameter are 4, 5 mm and type of woods are fugues oriental is, Alnus subcordata and white spruce on tension resistance and bending moment were tested. The dimensions for malting T- form joints were 5×5×2/5 wooden dowel used in this research was carpinus betulus which is the common dowel in malted. Also, Poly-vinyl acetate was used in Joints. The combination of above said factors in dowel joint 6 male totally 24 T sample by 4 repetitions and tension resistance and bending moment were measured by mechanical test machine. For exertion strength in order to analyze the aforementioned resistance, loading speed equal to 1.25 mm/min was used. Also, for analyzing the way of distribution and tension concentration in joint and changing process of tension base on changing the variables in this research finite element method and ANSYS Software were used. Based on the findings, the German modeling of joint which endures the maximum tension is equal to the type being used in real joints. Distribution of tension in the middle of the bending moment depths is maximum and tension in screw joints is consent Reid in failure Points.