Damping support fixture for vibration suppression in milling of thin-walled casing
Machining vibration is one of the main phenomenon occurs in milling of thin-walled workpiece, it will lead to poor surface finish and low machining efficiency. Especially for challenging situations such as large dimension closed casing, vibration is one of the main factors affecting the improvement of machining efficiency. In this work, a method by applying damping support fixtures for machining vibration suppression is developed. It can be mounted at different positions on the inner surface of casing to suppress vibration. This method has been validated by finite element simulation and cutting experiments. The results show that vibration can be suppressed with the presence of damping support fixtures. The new method can be used to get higher machining efficiency and better surface finish in milling of thin-walled casing.
Design and implementation of tuned viscoelastic dampers for vibration control in milling
Passive means of vibration attenuation have been employed successfully and efficiently in machining systems such as turning and milling. Traditional approach to controlling vibration in a milling s ...
Influence of filler addition, storage medium and evaluation time on biaxial flexure strength and modulus of adhesive systems
Abstract Objective. This study evaluated the effects of filler addition, storage medium and time on biaxial flexural strength and flexural modulus of six adhesive systems. Materials and methods. The adhesives were either unfilled resins: Single Bond, Prime&Bond 2.1 and One-Step; or filled resins: Single Bond Plus, Prime&Bond NT and One-Step Plus. Resin discs of each product (0.5 mm thick × 6.0 mm diameter) were prepared using silicon molds (n = 10). The discs were stored dry, in water, mineral oil or ethanol for 1 week or 3 months before biaxial flexural testing. Data were statistically analyzed by 3-way ANOVA and Tukey's post-hoc test (α = 0.05). The specimens were tested in a universal testing machine at 1.27 mm/min until failure occurred. Results. In general, the storage in ethanol led to significantly lower flexural strength and flexural modulus values than the other storage conditions for all adhesives in both storage periods. Filler addition increased flexural strength and flexural modulus for Prime&Bond NT, when it was stored dry or in water for 1 week. For Single Bond Plus, the filler addition resulted in higher flexural modulus, when it was stored for 1 week in oil and in ethanol. No significant differences in flexural modulus were observed between One-Step and One-Step Plus in any storage medium. Conclusions. Results suggested that filler addition does not necessarily have to increase the flexural strength and flexural modulus. Ethanol and oil storages tended to yield opposite effects.