Fracture Behavior of AA7075-AA6061 and AA7075-Cu Friction-Stir Welded Joints Containing Blunt V-Notches under...

Area of Science:

• Materials Science
• Mechanical Engineering
• Fracture Mechanics

Background:

• Fracture analysis of friction-stir welded (FSWed) alloys with V-notched joints is complex due to elastic-plastic behavior and significant plastic deformations.
• Existing elastic-plastic fracture criteria are often time-consuming for analyzing FSWed materials like AA7075-Cu and AA7075-AA6061.

Purpose of the Study:

• To predict the load-bearing capacity (LBC) of V-notched FSWed joints in AA7075-Cu and AA7075-AA6061 materials under mode I loading.
• To simplify fracture analysis by applying the equivalent material concept (EMC).

Main Methods:

• The equivalent material concept (EMC) was employed to model the actual materials as equivalent virtual brittle materials.
• Two brittle fracture criteria, maximum tangential stress (MTS) and mean stress (MS), were used to estimate the LBC.
• Experimental results were compared with theoretical predictions derived from EMC and the brittle fracture criteria.

Main Results:

• The study successfully applied the equivalent material concept (EMC) to simplify the fracture analysis of V-notched FSWed joints.
• Both the maximum tangential stress (MTS) and mean stress (MS) criteria, when combined with EMC, demonstrated accurate predictions of LBC.
• The proposed method provides a computationally efficient approach for estimating the fracture behavior of these advanced materials.

Conclusions:

• The combination of the equivalent material concept (EMC) with brittle fracture criteria (MTS and MS) offers an accurate and efficient method for predicting the load-bearing capacity of V-notched FSWed joints.
• This approach simplifies the complex elastic-plastic fracture analysis required for materials like AA7075-Cu and AA7075-AA6061.
• The findings are valuable for structural integrity assessments and design optimization in applications utilizing friction-stir welded aluminum alloys.