Figure 1 - available via license: Creative Commons Attribution 3.0 Unported

Content may be subject to copyright.

Source publication

The suspension system of the drum washing machine is the object of study. To reduce the vibration of drum washing machines during high-speed dehydration, a shape memory alloy is proposed to be used to make suspension spring. The spring stiffness can be controlled according to the characteristic that the elastic modulus of SMA varies with temperatur...

## Contexts in source publication

**Context 1**

... facilitate the calculation, the following assumptions are made for the suspension system: Ignoring the mass of the damper and the spring, both are regarded as ideal components, and the connection points on the box and the inner cylinder are fixed; the inner and outer cylinders are regarded as rigid bodies, ignoring deformation, and they are coaxial; the clothing eccentric mass is simplified to a particle of constant mass, and fixed on the wall of the inner drum; the suspension system performs the plane motion, ignoring the rotation and movement along the direction of the drum axis. According to the simplification and assumptions, the mechanical model of the suspension system is established, as shown in Figure 1. ...

**Context 2**

... that the stiffness coefficient of the SMA spring ranges from 5 N/mm to 13 N/mm and setting the eccentric clothing with masses of 1 kg, 2 kg, and 5 kg in Adams, the vibration of the outer cylinder is simulated as shown in Table 2. The experimental data are processed by MATLAB as shown in Analyzing the simulation experiment results, from Figure 5 and Figure 6, it can be seen that the horizontal and vertical amplitudes of each mass are reduced to varying degrees after using SMA variable stiffness suspension spring at different speeds; it is found from Figure 5 that the vibration reduction effect in the horizontal direction has no obvious relationship with the rotational speed, and the vibration reduction amplitude increases with the increase of the mass of eccentric clothing; from Figure 6, the damping effect in the vertical direction decreases with the increase of rotational speed, and the it is obvious when the eccentric clothing is heavy; according to the comparison in Figures 7 - 9, when the mass is small, the vibration amplitude at each rotational speed is basically the same, the greater the mass of eccentric clothing, the more intense the vibration at low speed, but the vibration reduction effect is better; it can be seen from Figure 10 that the optimal stiffness of the suspension spring is related to the rotation speed and the mass of eccentric clothing. By the theoretical derivation and experimental results, the current can be directly changed when the speed and the eccentric mass of the clothing change, and the stiffness coefficient of the SMA suspension spring can be adjusted, to realize the active vibration control of the suspension system. ...