390
K. Bo et al.
dangerous for service in this phase. After 34,000 cycle times, more AE signals with
higher energy were collected and the pressure was decreasing in pressure holding
stage, which demonstrates that the cylinder was cycled to failure and fiber fractured
at a large range.
In our study, the cylinder was cycled to failure and its pressure history in overall
life was known. After different cycle times, AE testing was performed to the cylinder.
By combining with results of cumulative hit number and AE energy after different
cycle numbers, accumulated impact damage of the cylinder leaded to a dramatic
increase in the amount of AE activity. A consistent correlation was obtained between
the structural condition of the cylinder and AE cumulative hit number and energy.
Therefore, AE testing can be used to detect impact damage of type 4 cylinder and
assess the extent of the damage in different stage.
33.4 Conclusions
The acoustic emission (AE) was used to monitor the impact damage of full-wrapped
composite cylinder with non-metallic liner after different cycle times. The following
conclusions can be drawn:
(a) AE technique can be capable of monitoring the initiation and accumulation of
impact damage events in this type of cylinder.
(b) The trend of cumulative hit number can directly reflect the accumulation of
impact damage in type 4 cylinder with impact damage after different cycle
times.
(c) Energy and cumulative hit number are effective AE signal discriminators for
impact damage evaluation.
Acknowledgements This work is financially supported by National Key Research and Development Program of China (Grant No. 2017YFC0805604).
References
1. ISO/TR 13086-4:2019, Gas cylinders-Guidance for design of composite cylinders-Part 4: Cyclic
fatigue of fibres and liners
2. G. Richard, F. Richard, Periodic inspection of composite wrapped pressure vessels using acoustic
emission. CINDE J. 5–13 (2005)
3. H.Y. Chou, A.P. Mouritz, Acoustic emission analysis of composite pressure vessels under
constant and cyclic pressure. Compos. Part A 70, 111–120 (2015)
4. L. Dong, J. Mistry, Acoustic emission monitoring of composite cylinders. Compos. Struct. 40(2),
149–158 (1998)
5. P.J. de Groot, P.A.M. Wijnen, R.B.F. Janssen, Real-time frequency determination of acoustic
emission for different fracture mechanisms in carbon/epoxy composites. Compos. Sci. Technol.
55(4), 405–412 (1995)
K. Bo et al.
dangerous for service in this phase. After 34,000 cycle times, more AE signals with
higher energy were collected and the pressure was decreasing in pressure holding
stage, which demonstrates that the cylinder was cycled to failure and fiber fractured
at a large range.
In our study, the cylinder was cycled to failure and its pressure history in overall
life was known. After different cycle times, AE testing was performed to the cylinder.
By combining with results of cumulative hit number and AE energy after different
cycle numbers, accumulated impact damage of the cylinder leaded to a dramatic
increase in the amount of AE activity. A consistent correlation was obtained between
the structural condition of the cylinder and AE cumulative hit number and energy.
Therefore, AE testing can be used to detect impact damage of type 4 cylinder and
assess the extent of the damage in different stage.
33.4 Conclusions
The acoustic emission (AE) was used to monitor the impact damage of full-wrapped
composite cylinder with non-metallic liner after different cycle times. The following
conclusions can be drawn:
(a) AE technique can be capable of monitoring the initiation and accumulation of
impact damage events in this type of cylinder.
(b) The trend of cumulative hit number can directly reflect the accumulation of
impact damage in type 4 cylinder with impact damage after different cycle
times.
(c) Energy and cumulative hit number are effective AE signal discriminators for
impact damage evaluation.
Acknowledgements This work is financially supported by National Key Research and Development Program of China (Grant No. 2017YFC0805604).
References
1. ISO/TR 13086-4:2019, Gas cylinders-Guidance for design of composite cylinders-Part 4: Cyclic
fatigue of fibres and liners
2. G. Richard, F. Richard, Periodic inspection of composite wrapped pressure vessels using acoustic
emission. CINDE J. 5–13 (2005)
3. H.Y. Chou, A.P. Mouritz, Acoustic emission analysis of composite pressure vessels under
constant and cyclic pressure. Compos. Part A 70, 111–120 (2015)
4. L. Dong, J. Mistry, Acoustic emission monitoring of composite cylinders. Compos. Struct. 40(2),
149–158 (1998)
5. P.J. de Groot, P.A.M. Wijnen, R.B.F. Janssen, Real-time frequency determination of acoustic
emission for different fracture mechanisms in carbon/epoxy composites. Compos. Sci. Technol.
55(4), 405–412 (1995)