The application of a thermal source in non-contact forming of sheet metal has long been used. However, the replacement of this thermal source with a laser beam promises much greater controllability of the process. This yields a process with strong potential for application in aerospace, shipbuilding, automobile, and manufacturing industries, as well as the rapid manufacturing of prototypes and adjustment of misaligned components. Forming is made possible through laser-induced non-uniform thermal stresses. In this letter, we use the geometrical transition from rectangular to circle-shaped specimen and ring-shaped specimen to observe the effect of geometry on deformation in laser forming. We conduct a series of experiments on a wide range of specimen geometries. The reasons for this behavior are also analyzed. Experimental results are compared with simulated values using the software ABAQUS. The utilization of line energy is found to be higher in the case of laser forming along linear irradiation than along curved ones. We also analyze the effect of strain hindrance. The findings of the study may be useful for the inverse problem, which involves acquiring the process parameters for a known target shape of a wide range of complex shape geometries. OCIS codes: 140.0140, 160.0160.

Laser forming is a new type of flexible manufacturing process that has become viable for the shaping of metallic components. Process designing of laser forming involves finding a set of process parameters, including laser power, laser scanning paths, and scanning speed, given a prescribed shape. To date, research has focused on process designing for rectangular plates, and only a few studies are presented for axis-symmetric geometries like circular plates. In the present study, process designing for axis-symmetric geometries-with focus on class of shapes-is handled using a formerly proposed distance-based approach. A prescribed shape is achieved for geometries such as quarter-circular and half-circular ring plates. Experimental results verify the applicability of the proposed method for a class of shapes.OCIS Compared with conventional forming techniques, laser forming of sheet metal does not require hard tooling or external forces. Such advantage can increase process flexibility and reduce the cost of the forming process when low-to medium-production volume is concerned.In recent years, laser-forming techniques have been extensively investigated. In some empirical studies, the relation between a bending angle and process parameters was analyzed [1−3] . However, the results were highly case-dependent. To overcome this shortcoming, a number of finite-element models were developed [4,5] . In Refs. [6,7], simplified relationships between the bending angle and process parameters by analytical models were proposed. Given process and material parameters, a vast majority of work on laser forming can be considered for solving the direct problem, that is, finding the spatial and temporal distribution of temperature, strain/stress state and ultimate deformation of a workpiece. To apply the laser-forming process to real-world problems, however, the inverse problem needs to be addressed, that is, designing process parameters and scanning path planning given a desired shape. Kyrsanidi et al. investigated the laser forming of a sine-shaped plate; however, the forming accuracy of the plate was lower due to the equal distance between the scanning paths and the fixed process parameters [8] . Hennige proposed a path strategy for ring and circle segments, but the range of the segment angle was limited [9] . Most of the research to date has focused on laser forming along linear irradiation paths and over rectangular plates. However, to advance the laser-forming process for realistic forming applications in a manufacturing environment, it is necessary to consider process designing for three-dimensional (3D) laser forming for a class of geometrical shapes. To decipher the inverse problem, Kim et al. developed two methods: distance-based (DB) and angle-based [10] . However, they implemented those techniques over rectangular plates only. The objective of the present research is to ascertain the applicability of the DB method [10] for non-rectangular simple geometry. This letter is concerned with process designing for a class of shapes...

Application of a thermal source in non-contact forming of sheet metal is known for some time. Replacement of this thermal source with a laser beam promises the much greater controllability of the process. To date, research focuses on dealing with rectangular plates, and only a few studies are presented for axis-symmetric geometries like circular plates. This study presents the work to get the dish or bowl shape by an initially flat circular plate. Two different scanning strategies circular and radial are attempted to get the desired dish shape. Following the unexpected distortion throughout the plate, a second series of experiments are conducted on a wide range of specimen geometries. An interesting phenomenon is observed. It is suggested that homogeneous dissemination of heat along with combined form of both of the scanning strategies, could have more potential to form dome shape.