Figure 1.
Transient thermal numerical analysis: (a) scheme; (b) computational model with boundary conditions.
Figure 1.
Transient thermal numerical analysis: (a) scheme; (b) computational model with boundary conditions.
Figure 2.
Temperature distribution on the opposite to the heating surface: (a) after 2 s from heating beginning; (b) after 780 s from the start of heating.
Figure 2.
Temperature distribution on the opposite to the heating surface: (a) after 2 s from heating beginning; (b) after 780 s from the start of heating.
Figure 3.
Average and maximum temperatures of the opposite to the heating polymer sheet surface.
Figure 3.
Average and maximum temperatures of the opposite to the heating polymer sheet surface.
Figure 4.
Transient structural numerical analysis: (a) scheme; (b) computational model with boundary conditions.
Figure 4.
Transient structural numerical analysis: (a) scheme; (b) computational model with boundary conditions.
Figure 5.
Modeling results of the second stage after 780 s from the heating beginning: (a) total deformation; (b) equivalent Von Mises stress.
Figure 5.
Modeling results of the second stage after 780 s from the heating beginning: (a) total deformation; (b) equivalent Von Mises stress.
Figure 6.
Average and maximum deformation under the earth gravity versus time of the polymer sheet.
Figure 6.
Average and maximum deformation under the earth gravity versus time of the polymer sheet.
Figure 7.
Experimental set-up for polymer sheet forming parameters validation: (a) scheme; (b) set-up view: 1—PVC ESA-D polymer sheet, 2—holding frame, 3—laser displacement meter Kyence LK-G82/3001 (Keyence Corporation, Neu-Isenburg, Germany), 4—digital oscilloscope PicoScope-6403 (Pico Technology Ltd., Cambridgeshire, UK), 5—PC, 6—hot air blowing system CT-850D (Acifica, Inc., San Jose, CA, USA), 7—thermal imaging camera FLIR T450sc (FLIR Systems Inc., Wilsonville, OR, USA).
Figure 7.
Experimental set-up for polymer sheet forming parameters validation: (a) scheme; (b) set-up view: 1—PVC ESA-D polymer sheet, 2—holding frame, 3—laser displacement meter Kyence LK-G82/3001 (Keyence Corporation, Neu-Isenburg, Germany), 4—digital oscilloscope PicoScope-6403 (Pico Technology Ltd., Cambridgeshire, UK), 5—PC, 6—hot air blowing system CT-850D (Acifica, Inc., San Jose, CA, USA), 7—thermal imaging camera FLIR T450sc (FLIR Systems Inc., Wilsonville, OR, USA).
Figure 8.
Experimental validation results: (a) polymer sheet temperature versus time; (b) polymer sheet displacement versus temperature.
Figure 8.
Experimental validation results: (a) polymer sheet temperature versus time; (b) polymer sheet displacement versus temperature.
Figure 9.
Excitation heat flow curve.
Figure 9.
Excitation heat flow curve.
Figure 10.
Transient thermal numerical analysis: (a) scheme; (b) computational model with boundary conditions.
Figure 10.
Transient thermal numerical analysis: (a) scheme; (b) computational model with boundary conditions.
Figure 11.
Temperature distribution on the opposite to the heating surface: (a) after 1.92 s from heating beginning; (b) after 120 s from the start of heating.
Figure 11.
Temperature distribution on the opposite to the heating surface: (a) after 1.92 s from heating beginning; (b) after 120 s from the start of heating.
Figure 12.
Modeling results: (a) average and maximum temperatures of the opposite to the heating polymer sheet surface; (b) average and maximum deformation under the earth gravity versus time of the polymer sheet.
Figure 12.
Modeling results: (a) average and maximum temperatures of the opposite to the heating polymer sheet surface; (b) average and maximum deformation under the earth gravity versus time of the polymer sheet.
Figure 13.
Modeling results of the second stage after 120s from the start of heating: (a) total deformation; (b) equivalent Von Mises stress.
Figure 13.
Modeling results of the second stage after 120s from the start of heating: (a) total deformation; (b) equivalent Von Mises stress.
Figure 14.
Polymer sheet SPIF tool: 1—metal sphere, 2—ring-shaped magnet, 3—waveguide, 4—ultrasonic vibration transducer-piezoceramic discs, 5—fiber optics, 6—temperature sensor.
Figure 14.
Polymer sheet SPIF tool: 1—metal sphere, 2—ring-shaped magnet, 3—waveguide, 4—ultrasonic vibration transducer-piezoceramic discs, 5—fiber optics, 6—temperature sensor.
Figure 15.
Polymer sheet SPIF with a laser heating: (a) schematics; (b) equipment: 1—metal sphere; 2—ring-shaped magnet; 3—waveguide; 4—ultrasonic vibration transducer-piezoceramic discs; 5—fiber optics; 6—temperature sensor, 7—laser diode module BMU25-940-01-R (Oclaro Inc., San Jose, CA, USA) with laser beam intensity controller Keithley 2230-30-1 (Keithley Instruments Inc., Cleveland, OH, USA), 8—ultrasonic vibration controller Sensotronica VT-400. (KTU, Kaunas, Lithuania).
Figure 15.
Polymer sheet SPIF with a laser heating: (a) schematics; (b) equipment: 1—metal sphere; 2—ring-shaped magnet; 3—waveguide; 4—ultrasonic vibration transducer-piezoceramic discs; 5—fiber optics; 6—temperature sensor, 7—laser diode module BMU25-940-01-R (Oclaro Inc., San Jose, CA, USA) with laser beam intensity controller Keithley 2230-30-1 (Keithley Instruments Inc., Cleveland, OH, USA), 8—ultrasonic vibration controller Sensotronica VT-400. (KTU, Kaunas, Lithuania).
Figure 16.
Experimental investigation of forming four geometric shapes from polymer sheet: (a) scheme; (b) stand view. Here: 1—PVC ESA-D polymer sheet, 2—holding frame, 3—robot ABB IRB1200 (ABB Robotics & Discrete Automation, Västerås, Sweden), 4—forming tool, 5—heat gun Toolland PHG2 (Tooland Inc., San Carlos, CA, USA), 6—thermal imaging camera FLIR T450sc (FLIR Systems Inc., Wilsonville, OR, USA), 7—PC.
Figure 16.
Experimental investigation of forming four geometric shapes from polymer sheet: (a) scheme; (b) stand view. Here: 1—PVC ESA-D polymer sheet, 2—holding frame, 3—robot ABB IRB1200 (ABB Robotics & Discrete Automation, Västerås, Sweden), 4—forming tool, 5—heat gun Toolland PHG2 (Tooland Inc., San Carlos, CA, USA), 6—thermal imaging camera FLIR T450sc (FLIR Systems Inc., Wilsonville, OR, USA), 7—PC.
Figure 17.
Thermal images of polymer sheet: (a) heated with air gun, (b) heated with advanced heating device.
Figure 17.
Thermal images of polymer sheet: (a) heated with air gun, (b) heated with advanced heating device.
Figure 18.
Photos of the incrementally formed polymer sheets of PVC ESA-D material was achieved by elevated temperature forming conditions: (a) spatial circular geometry; (b) spatial square geometry; (c) spatial flower geometry; (d) spatial star geometry.
Figure 18.
Photos of the incrementally formed polymer sheets of PVC ESA-D material was achieved by elevated temperature forming conditions: (a) spatial circular geometry; (b) spatial square geometry; (c) spatial flower geometry; (d) spatial star geometry.
Figure 19.
Schematics of a robotized polymer sheet SPIF step-by-step feedback system.
Figure 19.
Schematics of a robotized polymer sheet SPIF step-by-step feedback system.
Figure 20.
Dependence of the forming force on forming depth.
Figure 20.
Dependence of the forming force on forming depth.
Table 1.
Properties of the PVC Trovidur ESA-D material and geometric dimensions of the sheet used in calculation [
18].
Table 1.
Properties of the PVC Trovidur ESA-D material and geometric dimensions of the sheet used in calculation [
18].
Parameter | Value | Unit |
---|
Length × width of the sheet | 300 × 300 | mm |
Thickness of the sheet | 3 | mm |
Density | 1.41 | g/cm3 |
Tensile stress at yield | 47.75 | N/mm2 |
Elongation at break | 30.3 | % |
Modulus of elasticity in tension | 2643 | N/mm2 |
Notched Impact strength | 9.09 | mJ/mm2 |
Compressive strength | 65.4 | MPa |
Vicat-softening temperature | 75.0 | °C |
Coefficient of linear thermal expansion | 70 | 10−6/K |
Table 2.
FE numerical simulation data of the first stage of analysis.
Table 2.
FE numerical simulation data of the first stage of analysis.
Parameter | Value | Unit |
---|
Mesh elements method | Hex Dominant | - |
Number of finite elements | 3600 | - |
Number of nodal points | 25,803 | - |
Convection film coefficient of the heat gun surface area | 47 | W/m2 |
Convection temperature of the heat gun surface area | 80 | °C |
Convection film coefficient of the rest ambient surface area | 25 | W/m2 |
Convection temperature of the rest ambient surface area | 22 | °C |
Total time of calculation | 780 | s |
Table 3.
FE numerical simulation data of the second stage of analysis.
Table 3.
FE numerical simulation data of the second stage of analysis.
Parameter | Value | Unit |
---|
Mesh elements method | Hex Dominant | - |
Number of finite elements | 3600 | - |
Number of nodal points | 25,803 | - |
Input load | Temperature | °C |
Acceleration of gravity | 9806.6 | mm/s2 |
Total time of calculation | 780 | s |
Table 4.
Excitation heat flow parameters.
Table 4.
Excitation heat flow parameters.
Time, s | Heat Flow Power, W |
---|
0 | 0 |
0.18 | 4.5 |
3 | 2.2 |
50 | 0.05 |
120 | 0 |
Table 5.
FE numerical simulation data of the first stage of analysis.
Table 5.
FE numerical simulation data of the first stage of analysis.
Parameter | Value | Unit |
---|
Mesh elements method | Hex Dominant | - |
Number of finite elements | 15,124 | - |
Number of nodal points | 103,231 | - |
Heat flow application geometry | Ø10 mm circle | - |
Heat flow magnitude | Tabular (see Table 4) | W |
Convection film coefficient of the rest ambient surface area | 25 | W/m2 |
Convection temperature of the rest ambient surface area | 22 | °C |
Total time of calculation | 120 | s |
Table 6.
Experimental research data for incremental polymer sheet forming.
Table 6.
Experimental research data for incremental polymer sheet forming.
Parameter | Value | Unit |
---|
Radius of the forming tool sphere | 8.5 | mm |
Step down | 0.5 | mm |
Radial step | 0.5 | mm |
Total forming depth | 30 | mm |
Feed rate | 100 | mm/s |
Major diameter of the geometric figure | 150 | mm |
Minor diameter of the geometric figure | 90 | mm |
Minimum temperature of the surface | 40 | °C |
Maximum temperature of the surface | 60 | °C |