Academia.eduAcademia.edu

Figure 4 – uploaded by A. Di Ilio

See full PDFdownloadDownload figure
Fig. 4. Schematic representation of the shear lap sample with single joint. Dimen- sions are expressed in millimetres.

Figure 4 Schematic representation of the shear lap sample with single joint. Dimen- sions are expressed in millimetres.

Related Figures (15)

Fig. 1. (a) Schematic representation of preheating and subsequent clinching of thermoplastic and metal sheets. (b) Layout of the experimental equipment a = We ae ee) ee ene ne ieee FEELS EES A schematic representation of the clinching phases as well as the main quality criteria (neck thickness t, and interlock t;) is reported The present investigation is intended to assess the suitability of the mechanical clinching process to produce plastic-metal hybrid joints. To this end, a prototypal apparatus was developed to per- form a convective preheating and the subsequent clinching of the sheets. Clinched joints produced on an aluminium alloy AA5053T4 and polystyrene were investigated. A campaign of experimental tests was carried out to evaluate the influence of the main oper- ational conditions on joinability and mechanical behaviours of
Fig. 1. (a) Schematic representation of preheating and subsequent clinching of thermoplastic and metal sheets. (b) Layout of the experimental equipment a = We ae ee) ee ene ne ieee FEELS EES A schematic representation of the clinching phases as well as the main quality criteria (neck thickness t, and interlock t;) is reported The present investigation is intended to assess the suitability of the mechanical clinching process to produce plastic-metal hybrid joints. To this end, a prototypal apparatus was developed to per- form a convective preheating and the subsequent clinching of the sheets. Clinched joints produced on an aluminium alloy AA5053T4 and polystyrene were investigated. A campaign of experimental tests was carried out to evaluate the influence of the main oper- ational conditions on joinability and mechanical behaviours of
Experimental factors and ranges of variation. Table 1 values of the joining load (F;), six values of the heating time (t,) and two values of air temperature (T,j,), as summarized in Table 1.
Experimental factors and ranges of variation. Table 1 values of the joining load (F;), six values of the heating time (t,) and two values of air temperature (T,j,), as summarized in Table 1.
Fig. 2. Picture of the clinching machine used in the experimental tests.
Fig. 2. Picture of the clinching machine used in the experimental tests.
Fig. 3. Schematic representation of adopted clinching tools.
Fig. 3. Schematic representation of adopted clinching tools.
Fig. 5. Variation of joining temperature with pre-heating time and temperature o heater.
Fig. 5. Variation of joining temperature with pre-heating time and temperature o heater.
Fig. 6. SEM macrograph of a clinched connection produced with T,;, = 400°C, t, =2s and joining load Fj = 11 kN.
Fig. 6. SEM macrograph of a clinched connection produced with T,;, = 400°C, t, =2s and joining load Fj = 11 kN.
Fig. 7. Cross section of polymer-metal clinched connections produced with air tem- perature T,;,=400°C with different heating times (a) t, =2s and (b) t,=10s. (For interpretation of the references to colour in this figure citation in the text, the reader is referred to the web version of this article.)
Fig. 7. Cross section of polymer-metal clinched connections produced with air tem- perature T,;,=400°C with different heating times (a) t, =2s and (b) t,=10s. (For interpretation of the references to colour in this figure citation in the text, the reader is referred to the web version of this article.)
Fig. 8. Macrograph of polymer (die-sided sheet) in a clinched connection with excessive preheating.
Fig. 8. Macrograph of polymer (die-sided sheet) in a clinched connection with excessive preheating.
Fig. 10. Joinability window with different temperature of heating air T,,,. (For inter- pretation of the references to colour in this figure citation in the text, the reader is referred to the web version of this article.) According to the achieved results, the joining load shows a threshold values of 9kN below which the interlock is not formed, as shown in Fig. 10. The threshold value was independent of the pre-heating conditions. Actually, the joining force mainly depends on the flow stress of the metal sheet, which is at least one order of magnitude higher than that of the softened polymer. Therefore, the decrease in the yield stress of the polymer achieved with a pro- longed heating time or a higher temperature T,;, does not alter the minimum required joining load during clinching.
Fig. 10. Joinability window with different temperature of heating air T,,,. (For inter- pretation of the references to colour in this figure citation in the text, the reader is referred to the web version of this article.) According to the achieved results, the joining load shows a threshold values of 9kN below which the interlock is not formed, as shown in Fig. 10. The threshold value was independent of the pre-heating conditions. Actually, the joining force mainly depends on the flow stress of the metal sheet, which is at least one order of magnitude higher than that of the softened polymer. Therefore, the decrease in the yield stress of the polymer achieved with a pro- longed heating time or a higher temperature T,;, does not alter the minimum required joining load during clinching.
Fig. 9. Failures behaviours occurring during clinching: (a) insufficient forming load and (b) shearing of the metallic button.
Fig. 9. Failures behaviours occurring during clinching: (a) insufficient forming load and (b) shearing of the metallic button.
Fig. 11. Load displacement curve for pull-out, neck fracture and net tension failure modes.
Fig. 11. Load displacement curve for pull-out, neck fracture and net tension failure modes.
Fig. 12. Rupture modes: (a) net tension of plastic; (b) neck fracture of metal.
Fig. 12. Rupture modes: (a) net tension of plastic; (b) neck fracture of metal.
Fig. 13. Crack development in metal sheet neck: (a) F,=14KN, (b) Fj =18 KN. (For interpretation of the references to colour in this figure citation in the text, the reader is referred to the web version of this article.)
Fig. 13. Crack development in metal sheet neck: (a) F,=14KN, (b) Fj =18 KN. (For interpretation of the references to colour in this figure citation in the text, the reader is referred to the web version of this article.)
Fig. 14. Effect of joining force on (a) shear strength and (b) interlock and neck thickness.
Fig. 14. Effect of joining force on (a) shear strength and (b) interlock and neck thickness.
Fig. 15. Effect of pre-heating time on (a) shear strength and (b) interlock and neck thickness.
Fig. 15. Effect of pre-heating time on (a) shear strength and (b) interlock and neck thickness.
Related topics:
Materials EngineeringMechanical EngineeringMaterials ScienceManufacturing EngineeringJoining of MaterialsMetal Clinching
580 California St., Suite 400
San Francisco, CA, 94104
© 2025 Academia. All rights reserved