This paper presents a review on the formability evaluation of AHSS, enhancing necking-based failure criteria limitations. Complementary fracture/damage constitutive modeling approaches specifically tailored to formability evaluation, validated through numerical and experimental methods, are also subjects of research. AHSS are widely processed through sheet metal forming processes. Although an excellent choice when lightweight, high-strength, and ductility are critical factors, their multi-phase microstructure accentuates forming challenges. To accurately model forming behavior, necking-based failure criteria as well as direct fracture models require improvements. As a necking-based failure model, the conventional forming limit diagram/curve (FLD/FLC) presents limitations in estimating direct fracture (surface cracks, edge cracks, shear cracks), as well as deformation histories under non-linear strain paths. Thus, significant research efforts are being made towards the development of advanced fracture constitutive models capable of predicting fracture scenarios without necking, which are more frequently observed in the realm of AHSS. Scientific community research is divided into several directions aiming at improving the forming and fracture behavior accuracy of parts subjected to sheet metal forming operations. In this review paper, a comprehensive overview of ductile fracture modeling is presented. Firstly, the limitations of FLD/FLC in modeling fracture behavior in sheet metal forming operations are studied, followed by recent trends in constitutive material modeling. Afterwards, advancements in material characterization methods to cover a broad range of stress states are discussed. Finally, damage and fracture models predicting failure in AHSS are investigated. This review paper supplies relevant information on the current issues the sheet metal forming community is challenged with due to the trend towards AHSS employment in the automotive industry.

This paper presents a review on numerical and experimental methods to predict fracture of ad-vanced high strength steels (AHSS). AHSS are widely processed through sheet metal forming processes. Although being an excellent choice when lightweight, high strength and ductility are critical factors, their multi-phase microstructure accentuates forming challenges. To accurately model forming behavior, necking based failure criteria as well as direct fracture models require improvements. As a necking based failure model, the conventional forming limit diagram/curve (FLD/FLC) presents limitations such as in estimating direct fracture (surface cracks, edge cracks, shear cracks), as well as deformation histories under nonlinear strain paths. Thus, significant re-search efforts are being made towards the needs of advanced fracture constitutive models capa-ble of predicting fracture scenarios without necking, more frequently observed in the realm of AHSS. Scientific community research is divided into several directions aiming at improving the forming and fracture behavior accuracy of parts subjected to sheet metal forming operations. In this review paper, a comprehensive overview on ductile fracture modeling is presented. Firstly, the FLD/FLC limitations modeling fracture behavior in sheet metal forming operations are stud-ied. Followed by the recent trends in constitutive material modeling. Afterwards, material char-acterization methods advancements to cover a broad range of stress states are comprised. Final-ly, damage and fracture models predicting failure in AHSS are investigated. This review paper supplies relevant information on the current issues the sheet metal forming community is chal-lenged with due to the trend towards AHSS employment in the automotive industry.

Information is presented on the conceptualization, experimental study, and numerical process simulation of tailor heat treated aluminum alloy blanks. This concept is intended to improve the forming behavior of aluminum parts in challenging conditions. The implementation requires precise control of laser heat treatment parameters within a suitable industrial framework. The study details material properties, heat treatment parameters, and experimental results for the strength and elongation properties of an AA6063-T6 aluminum alloy. Constitutive modeling is applied using the Hocket–Sherby equation, which allowed us to establish a correlation between laser heat treatment maximum temperature and the corresponding material softening degree. Based on the generated flow stress–strain curves, a numerical simulation of a representative case study was performed with Abaqus finite element software highlighting potential improvements of tailor heat treated blanks (THTB). The influence and effectiveness of heat-affected zone (HAZ) dimensions and material softening were analyzed.

This paper presents information and results relevant for the development of a laser heat treatment process suitable to improve manufacturing in high strength steel and high strength aluminium alloys. The challenges with manufacturing of such materials include springback effect and localised fracture. The study details heat cycle and their effect in metallurgical state and mechanical properties. Such laser induced heat treatment process is intended to improve the forming behaviour of metal parts in challenging metal forming conditions, in particular for the delay or avoidance of localised fracture. Results for strength, hardness and elongation properties are presented. It was concluded that it is possible to locally modify yield strength and hardness using process duration suitable for industrial applications. Suitable process temperature ranges and target heat cycles were identified. A positive effect of material softening was observed in both hardness and strength properties. However, in some cases a reduction of ductility is apparent which must be considered for targeted industrial applications. The dimension of the heat-affected zone was also considered as design variable for the industrial process development. Preliminary results were obtained in a development forming tool.

This study presents information regarding the development of a localized laser-induced heat treatment for aluminum alloys. Such a process is intended to improve the forming behavior of aluminum parts in challenging metal-forming conditions. This stud...

This study presents a Digital Image Correlation (DIC)-based experimental framework for the calibration of the Hosford-Coulomb (HC) and Modified-Mohr Coulomb (MMC) damage initiation criteria in an Advanced High Strength Steel (AHSS) DP1000. Three characteristic loading conditions in sheet metal forming—pure shear, uniaxial tension, and plane strain tension—were reproduced using flat specimens in a universal tensile testing machine, thus eliminating the need for costly and time-consuming tooling systems. An additional notch tension specimen was employed to validate the stress-state sensitivity of the proposed calibration approach. By integrating full-field strain data from DIC with tensile test results, stress–strain relationships were directly obtained without finite element modeling. The results confirm the effectiveness of dogbone, mini shear, and plane strain tension specimens in achieving proportional loading path histories up to fracture initiation, with constant stress state evolution during deformation. Comparison of the HC and MMC damage criteria reveals similar fracture loci, with the HC model exhibiting slightly higher resistance between shear and uniaxial tension conditions. This study discusses the suitability of a fully experimental DIC-based methodology for the calibration of stress-state-dependent damage initiation criteria. The results highlight the ability of the proposed methodology as a simplified and lower time-consuming alternative to traditional numerical assisted frameworks.