Airbag Burst testing is used to determine the absolute maximum pressure at which ship launching airbags will “burst” or fail catastrophically. It is the ultimate test method for the Ship Launching airbags’performance and safety.
Airbag burst test is invaluable for airbag design engineers to assist with material selection, wall thickness, or component geometry, structure optimization etc. This test can be used to determine the pressure at which a component or assembly begins to plastically deform and its ultimate tensile strength, then help manufacturers to establish safety design margins.
Identifying the maximum burst pressure is critical to decide the safety factor of ship launching airbags. Marine airbags usually are used in the open site and exposed to personnel, safety is always most concerned for both manufacturers and customers.
Evergreen Maritime conducts hydrostatic burst testing by using water to his marine airbags regularly by production lot or each time main material batch change to monitor the production and quality control. Burst testing is conducted using a plc controlled, monitored, and computer regulated test bench; featuring data acquisition at 50 Hz, calibrated pressure transducer, and protective safety features.
Benefits of Burst Testing of Ship Launching Airbags
- Identify the maximum burst pressure
- Meet quality standards ‘factor of safety’ standards
- Confirm design margin of production part
- Determine failure mode (the way in which a part fails)
- Find the ‘weakest link’ in a production or assembly
Burst Testing Report of Ship Launching Airbags with 2.0 m diameter
Experiment Info
Object: Marine airbag ( D 2.0 M x L 10 M, 6-layer),two pieces
Location: backyard of Evergreen Maritime NO.1 factory
Random selected airbags from two batches are tested at one time
Facilities:
CCTV, Pump WQ10-10-1, Tape ruler, Pressure Gauges
Results:
| Test Pressure | Pressure keeping Time | Result |
| 0.1 Mpa | 30 minutes | No change of dimension |
| 0.2 Mpa | 60 minutes | Diameter increases 2%, length increases 2.5 %, no crack occur |
| 0.3 Mpa | 120 minutes | Diameter increases 4%, length increases 5%, no crack occur |
| 0.4 Mpa | 24 Hours | Diameter increases 5%, length increases 6%, no crack occur, no bursting |
| 0.6 Mpa | 1 hour | Diameter increases 7%, length increases 7%, tiny cracks occur, no bursting |
Analysis
The tested two pieces airbags keep pressure at 0.6 mPa for one hour and did not burst.
The rated working pressure of diameter 2.0 m airbag is 0.1 MPa, So safety factor of marine airbags with 2.0 m diameter and 6 reinforcement layers is at least 6 times.
The ISO standards of ship launching airbags ISO 14409 asks for safety factor is 3 times, Evergreen performs a higher standards for his products.
