Incremental Forming Techniques for Sheet Metal Structures

Incremental forming techniques have emerged as flexible and cost-effective alternatives to traditional stamping and die-based methods in the production of sheet metal components. Unlike conventional processes that impose global deformation through rigid dies, incremental forming shapes the sheet progressively using a small, often spherical tool that follows a preprogrammed path. This localised deformation enables the manufacture of complex geometries without dedicated tooling, reducing lead times and accommodating small production batches and customised designs. Variants such as single-point incremental forming (SPIF) and double-sided incremental forming (DSIF) differ in whether deformation is applied to one or both sides of the sheet, influencing formability, surface finish and mechanical behaviour. Recent advances have addressed key challenges in form accuracy, thinning and fracture by refining tool path strategies, developing analytical and numerical models for force and strain prediction, and integrating novel materials and hybrid machine learning approaches. These developments underscore a global trend towards digitisation of forming processes, real-time process control and sustainable manufacturing practices that highlight incremental forming’s potential in aerospace, medical implants and lightweight automotive components.

Research from Nature Portfolio

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Research from all publishers

Recent studies have deepened understanding of deformation and fracture mechanisms by simulating cyclic bending plus compression in SPIF and DSIF. By integrating a modified damage model that captures stress path transitions between equi-biaxial and plane strain conditions, researchers achieved accurate predictions of fracture depth and elongation with errors below 8 per cent. Separately, an analytical force prediction model now accounts for local contact states and global bending, reproducing both peak and stabilised force histories across different part geometries. Validation on truncated cones and cranial plate prototypes confirms its broad applicability. In a distinct line of work, machine learning has been married with incremental forming through a generalisable tool path planning strategy. Leveraging deep reinforcement and supervised learning, the system autonomously predicts optimal tool trajectories for arbitrary two-dimensional profiles, demonstrating self-learning capabilities and significant improvements in path generalisation without prior metal forming knowledge.

Incremental Forming Techniques for Sheet Metal Structures publication trend

The graph below shows the total number of articles in incremental forming techniques for sheet metal structures across all publications each year (not limited to Nature Index journals).

Technical terms

Incremental sheet forming: A flexible forming process that deforms sheet metal locally by moving a simple tool along a predefined path rather than using shaped dies.

Single-Point Incremental Forming (SPIF): An incremental forming variant in which deformation is applied from one side of the sheet using a single tool, enabling high geometric flexibility.

Double-Sided Incremental Forming (DSIF): An incremental forming variant in which tools on both sides of the sheet apply deformation, improving surface finish and formability.

Finite Element Method (FEM): A numerical technique that subdivides complex structures into discrete elements to simulate stresses, strains and deformations under applied loads.

Stress triaxiality: A dimensionless measure of the ratio of hydrostatic stress to von Mises equivalent stress, influencing fracture and ductility in metal forming.

References

1. Deformation mechanisms and fracture in tension under cyclic bending plus compression, single point and double-sided incremental sheet forming processes. International Journal of Machine Tools and Manufacture (2023).
2. A new analytical model for force prediction in incremental sheet forming. Journal of Materials Processing Technology (2023).
3. A generalisable tool path planning strategy for free-form sheet metal stamping through deep reinforcement and supervised learning. Journal of Intelligent Manufacturing (2024).