Pittaya Akarasanon. Damping elements with shape memory effect for automotive safety systems. Master's Degree(Production Engineering). King Mongkut's University of Technology North Bangkok. Central Library. : King Mongkut's University of Technology North Bangkok, 2012.
Damping elements with shape memory effect for automotive safety systems
Abstract:
Currently, the seat belt system has many mechanical devices work together in order to reduce injuries caused by accidents such as the pretensioner, the load limiter, the retractor and the self-adaptive seat belt load limiter.
Researchers have studied the unique properties of Shape Memory Alloys (SMA). These properties are the shape memory effect (SME) and pseudo-elasticity (SE). These properties require an external heat or/and an external force to achieve the properties. Moreover, they also have an important property that can be used for the energy absorption: the damping capacity. The energy is absorbed in order to transform the internal structure. The damping properties of the shape memory alloys can be used in application of the load limiter and the pretensioner as well as in other applications of the automotive safety system.
To study the possibility of using SMAs in the automotive application, in this research two types of SMAs: NiTi-actuator wire specimens (0.1, 0.2, 0.3, 0.4 and 0.5 mm, diameter) and NiTi-pseudo-elastic wire specimens (0.127, 0.18, 0.25, 0.3 and 0.5 mm, diameter) were tested in different condition: to identify the mechanical properties of the both specimen types with different constant temperature at low speeds, to identify the electrical energy consumption of the NiTi-actuator wire specimens with activation time in 1 second with different constant stresses and different activated electrical energy and to identify the shape memory effects, pseudo-elastic properties, recovery percentages and damping properties of the both specimen types with different loading energy in high speed condition.
At this place it can be stated, that the results achieved in this work are indicating a successful application of shape memory elements as actuator and damping elements in automotive safety systems. The results also are indicating a performance of the drom impact testing machine in order to test SMA elements at very high speed.