1 Introduction
2 Theory of Manufacturing Process for the CNG Composite Pressure Vessel -Type II
2.1 D.D.I. Process
Parameter | Value |
---|---|
Thickness of initial blank t0 (mm) | 12.5 |
Diameter of initial blank D0 (mm) | 1100 |
Thickness of liner tf = t32 (mm) | 4 |
Inner diameter of liner Din = dp3 (mm) | 306 |
Outer diameter of liner Dout (mm) | 314 |
Length of liner L (mm) | 1830 |
1st stage (Cup drawing) | |||||
dp1 (mm) | 510.69 |
b
1
| 2.10 | ||
dd1 (mm) | 536.94 | A1 (mm2) | 20569.95 | ||
2nd stage (D.I.I.) | |||||
dp2 (mm) | 380.25 |
b
2
| 1.33 | ||
dd21 (mm) | 405.25 | t21 (mm) | 12.50 | A21 (mm2) | 15423.20 |
di22 (mm) | 401.19 | t22 (mm) | 10.47 | A22 (mm2) | 12584.09 |
di23 (mm) | 397.10 | t23 (mm) | 8.42 | A23 (mm2) | 10287.97 |
3rd stage (D.I.) | |||||
dp3 (mm) | 306.00 |
b
3
| 1.23 | ||
dd31 (mm) | 322.00 | t31 (mm) | 8.00 | A31 (mm2) | 7893.78 |
di32 (mm) | 314.00 | t32 (mm) | 4.00 | A32 (mm2) | 3895.57 |
2.2 Filament Winding Process
2.3 Curing Process
3 Finite Element Analysis for Manufacturing Processes of the Composite Pressure Vessel-Type II
3.1 Finite Element Analysis of D.D.I. Process
3.1.1 Modeling and Boundary Conditions
Die height (mm) | Inflow angle (°) | Die height (mm) | Inflow angle (°) |
---|---|---|---|
375 | 18.1 | 575 | 7.8 |
400 | 15.2 | 600 | 7.1 |
425 | 13.6 | 625 | 6.4 |
450 | 12.2 | 650 | 5.7 |
500 | 10.9 | 700 | 5.2 |
525 | 9.8 | 725 | 4.8 |
550 | 8.8 | 750 | 4.5 |
3.1.2 Result and Discussion
Fold check of the final workpiece | Forming load according to time | |
---|---|---|
1st stage (deep drawing) | ||
2nd stage (D.I.I.) | ||
3rd stage (D.I.) |
3.2 Finite Element Analysis of Composite Layer
3.2.1 Modeling and Boundary Conditions
3.2.2 Result and Discussion
Thickness of composite layer (mm) | Maximum equivalent stress of liner (MPa) | Maximum Tsai-Hill value of composite layer |
---|---|---|
5 | 871.92 | 1.11 |
6 | 842.48 | 1.00 |
6.3 | 834.18 | 0.96 |
6.6 | 826.08 | 0.92 |
7 | 815.91 | 0.87 |
3.3 Finite Element Analysis of Curing Process
3.3.1 Modeling and Boundary Conditions
Property | E-glass fiber | Epoxy resin |
---|---|---|
Density (kg/m3) | 2540 | 1225 |
Specific heat (J/(kg·°C)) | 712 | 967 |
Thermal conductivity (W/(m·°C) | 8.67 | 0.14 |
Elasticity modulus (Pa) | 3.05 × 1011 | 1 × 109 |
Poisson's ratio | 0.2 | 0.3 |
Thermal expansivity (1/°C) | 1.5 × 10−6 | 2.5 × 10−6 |
3.3.2 Result and Discussion
1st heating stage | 2nd heating stage | 3rd heating stage | |
---|---|---|---|
Temperature (°C) | 80 | 140 | 180 |
Heating rate (°C/s) | 0.04 | 0.03 | 0.02 |
Heating time (s) | 0‒2000 | 5000‒7000 | 10000‒12000 |