Investigation of the energy conversion efficiency of shape memory alloys
This project investigated the energy conversion efficiency of one way shape memory alloys (SMA). Energy conversion works by converting low grade thermal energy to mechanical energy, hence providing alternative sources of energy, useful to mankind. SMA energy conversion is however limited by its effi...
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| Format: | Final Year Project (FYP) |
| Language: | English |
| Published: |
2014
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| Online Access: | http://hdl.handle.net/10356/61441 |
| _version_ | 1811677085507256320 |
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| author | Lewis, Kingsley Earle |
| author2 | Liu Yong |
| author_facet | Liu Yong Lewis, Kingsley Earle |
| author_sort | Lewis, Kingsley Earle |
| collection | NTU |
| description | This project investigated the energy conversion efficiency of one way shape memory alloys (SMA). Energy conversion works by converting low grade thermal energy to mechanical energy, hence providing alternative sources of energy, useful to mankind. SMA energy conversion is however limited by its efficiency, hence prompting the need for accurate determination of the efficiency. The effects of pre-strain, constrained stress and heating rate on experimental efficiency were examined while the effects of constrained stress and recovery strain on theoretical efficiency were examined. The SMA wires underwent annealing followed by calorimetry to determine the transformation temperatures. Two types of deformation procedures were then used, namely fixed pre-strain with different constrained stresses and fixed constrained stress with changing pre-strains. Upon being loaded with the pre-strain, they were unloaded and reloaded with the constrained stress. Once the constrained stress was reached, the SMA wire was heated and the recovery strain was evaluated for efficiency calculations. Experimental efficiencies of 0.017- 0.102% were obtained compared to that of 1.11- 4.41% obtained theoretically. Experimental results suggested that efficiency increased with increasing pre-strain, constrained stress and the heating rate. However, at 13% pre-strain, the experimental efficiency reduced across all constrained stresses. Theoretical efficiencies showed increasing trend with increasing constrained stress and recovery strain. The following experimental and theoretical results will provide deep understanding of the energy conversion efficiency of NiTi SMA wire. |
| first_indexed | 2024-10-01T02:31:46Z |
| format | Final Year Project (FYP) |
| id | ntu-10356/61441 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T02:31:46Z |
| publishDate | 2014 |
| record_format | dspace |
| spelling | ntu-10356/614412023-03-04T18:50:19Z Investigation of the energy conversion efficiency of shape memory alloys Lewis, Kingsley Earle Liu Yong School of Mechanical and Aerospace Engineering DRNTU::Engineering This project investigated the energy conversion efficiency of one way shape memory alloys (SMA). Energy conversion works by converting low grade thermal energy to mechanical energy, hence providing alternative sources of energy, useful to mankind. SMA energy conversion is however limited by its efficiency, hence prompting the need for accurate determination of the efficiency. The effects of pre-strain, constrained stress and heating rate on experimental efficiency were examined while the effects of constrained stress and recovery strain on theoretical efficiency were examined. The SMA wires underwent annealing followed by calorimetry to determine the transformation temperatures. Two types of deformation procedures were then used, namely fixed pre-strain with different constrained stresses and fixed constrained stress with changing pre-strains. Upon being loaded with the pre-strain, they were unloaded and reloaded with the constrained stress. Once the constrained stress was reached, the SMA wire was heated and the recovery strain was evaluated for efficiency calculations. Experimental efficiencies of 0.017- 0.102% were obtained compared to that of 1.11- 4.41% obtained theoretically. Experimental results suggested that efficiency increased with increasing pre-strain, constrained stress and the heating rate. However, at 13% pre-strain, the experimental efficiency reduced across all constrained stresses. Theoretical efficiencies showed increasing trend with increasing constrained stress and recovery strain. The following experimental and theoretical results will provide deep understanding of the energy conversion efficiency of NiTi SMA wire. Bachelor of Engineering (Mechanical Engineering) 2014-06-10T05:59:22Z 2014-06-10T05:59:22Z 2014 2014 Final Year Project (FYP) http://hdl.handle.net/10356/61441 en Nanyang Technological University 65 p. application/pdf |
| spellingShingle | DRNTU::Engineering Lewis, Kingsley Earle Investigation of the energy conversion efficiency of shape memory alloys |
| title | Investigation of the energy conversion efficiency of shape memory alloys |
| title_full | Investigation of the energy conversion efficiency of shape memory alloys |
| title_fullStr | Investigation of the energy conversion efficiency of shape memory alloys |
| title_full_unstemmed | Investigation of the energy conversion efficiency of shape memory alloys |
| title_short | Investigation of the energy conversion efficiency of shape memory alloys |
| title_sort | investigation of the energy conversion efficiency of shape memory alloys |
| topic | DRNTU::Engineering |
| url | http://hdl.handle.net/10356/61441 |
| work_keys_str_mv | AT lewiskingsleyearle investigationoftheenergyconversionefficiencyofshapememoryalloys |