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6.2.2 Determination of sensitivity vectors from dewarping mapping
coefficients ………………………………………………………119
6.3 Calculation of orthogonal displacement gradient components ………….121
6.3.1 The sensitivity matrix ………………………………………........122
6.3.2 Effect of viewing configuration on the sensitivity matrix condition
number …………………………………………………………..124
6.3.3 Calculation of orthogonal displacement derivatives using simulated
phase maps ………………………………………………………126
6.4 Displacement gradient measurements of statically loaded objects ……...128
6.4.1 Measurements from the aluminium plate ………………………..128
6.4.2 Measurements from the perspex plate …………………………..130
6.4.3 Horizontal lines through subtracted images …………………….133
6.5 Measurements using the spatial carrier technique …………………........134
6.5.1 Calculation of shear magnitude variation using image
correlation………………………………………………………..135
6.5.2 Orthogonal displacement gradient components ………………...139
6.6 Summary ………………………………………………………………...139
References …………………………………………………………………...141
7. Measurement of Surface strain from dynamic objects ……………………..142
7.1 Measurements from a rotating object …………………………………...142
7.1.1 The test object …………………………………………………...143
7.1.2 The viewing apparatus frame ……………………………………143
7.1.3 Laser synchronization …………………………………………...146
7.1.4 Measurements from the rotating sample ………………………...147
7.2 Dual-pulse measurements from a vibrating test object ………………….151
7.2.1 The test object …………………………………………………...152
7.2.2 Dual-pulse operation ……………………………………………152
7.2.3 Laser synchronization …………………………………………...153
7.2.4 Measurements from the vibrating test object ……………………155
7.3 Summary ………………….……….……….……….……….……….….156
References ………………….……….……….……….……….……….…….157
8. Conclusions and future work ……………………..……..……..……..………158
8.1 Conclusions…………………………………..……….……….….……...158
8.2 Future work………………….……….……….……….……….………...161
8.2.1 Surface strain measurement from non-planar objects …………..161
8.2.2 Combined ESPI and shearography ……………………………...163
8.2.3 Improvements in signal processing ……………………………...164
8.3 References ………………….……….……….……….……….…………166
List of Publications ……………………..……..……..……..…………..………..167
Appendix A: Matlab for fringe pattern simulation ……………………..……..168
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