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Tubular Hydroforming and Hydropiercing
Published in R. Ganesh Narayanan, Jay S. Gunasekera, Sustainable Material Forming and Joining, 2019
Figure 10.38a displays the principle of rotary-draw bending with and without application of an axial force. The magnitude of the applied axial force has a significant effect on the strains during tube bending. As shown in Figure 10.38b, the maximum strain on the outer surface of the bent region decreases dramatically with increasing axial force. However, the strain on the inner surface increases significantly with increasing axial force. Note that the maximum strain on the outer surface is tensile, while the maximum strain on the inner surface is compressive. Figure 10.38b signifies that if a sufficiently high axial force is applied at the tube end, while the tube is rotary-draw bent, the amount of thinning on the outer surface is decreased significantly and the tube thickens intensely on the inner surface.
Knowledge-based expert system in manufacturing planning: state-of-the-art review
Published in International Journal of Production Research, 2019
Chan et al. (2003) developed KBS ‘IKB-MOULD’ to assist the design off injection mould for polymer part production and it integrates design and knowledge management modelling environment. Tor, Britton, and Zhang (2005) presented KB blackboard architecture for stamping PP. Object oriented feature modelling was incorporated for part modelling and stamping operation mapped with feature objects. Graph-based approach incorporated for process plan generation. Prototype system was developed through ‘CLIP’ ES cell and the effectiveness of the system validated through case study. Jin, Luo, and Fang (2001) proposed KBS to assist decision-making in tube bending process. Object oriented concept and goal driven search mechanism featured by graphical user interface were applied for the development of KBS. It is inferred that, proposed system minimises the inaccuracy in tube bending process. Kim, Kim, and Choi (2001) proposed a system for hot forging and blanking operations. CAPP system written on Auto-LISP and drafting language were used for implementation. Blank complexity, punch and die profiles, press availability and standards parts were taken into consideration for KBS development. Observed results enable the forging and blanking die designer and manufacturer to produce defect free components.
A study on localized expansion defects in tube hydroforming
Published in Journal of the Chinese Institute of Engineers, 2018
Sin-Liang Lin, Zih-Wei Chen, Fuh-Kuo Chen
The forming process for manufacturing the trailing arm of the front subframe involves bending, preforming, and hydroforming. Finite-element models for simulating these three forming processes were constructed. A four-node shell element was adopted to generate the finite-element mesh for the tube, and dies used to manufacture this trailing arm were considered rigid bodies. Convergence tests were conducted to determine a suitable mesh size for the finite-element simulations. To realize accurate simulations, this study used the actual mandrel shape and position to approximate the forming mechanism in the actual tube bending process. The mandrel is located 20 mm from the starting point. The pressure and feed parameters in the simulations were the same as those in the actual production.
Selection of process parameters in a single-pass laser bending process
Published in Engineering Optimization, 2018
Optimization of process parameters using soft computing techniques has also attracted the attention of researchers. Cheng and Lin (2000b) used an artificial neural network (ANN) to predict the bend angle of sheet metal, and developed regression models. Liu and Yao (2002) used response surface methodology as an optimization tool to determine a set of process parameters for obtaining a desired shape of sheet metal. Jung and Krumdieck (2007) obtained an optimal set of process parameters to produce a desired bend angle in the laser forming process with a constraint on the maximum temperature. Guan et al. (2013) developed an optimization procedure for the laser tube bending process by integrating the FEM simulation process with the genetic algorithm. Two different objective functions, i.e., maximum bend angle and desired bend angle, with a constraint on the maximum temperature were proposed. However, the issue of multiple solutions is not addressed in Jung and Krumdieck (2007) or Guan et al. (2013). Making use of ANN, Lambiase, Di Ilio, and Paoletti (2015) optimized the process parameters (laser power, scan speed and number of scans) to produce a desired bend angle in the minimum processing time. They used a constant laser beam of 3.6 mm × 0.8 mm spot size. In further work, they demonstrated that in a multi-pass laser forming process, the production rate can be increased 10-fold by employing water cooling between two passes (Lambiase, Di Ilio, and Paoletti 2016). Consideration of residual stress, radius of curvature, temperature-affected zone (TAZ) and line energy is also a requirement for sustainable and quality laser forming. There is a need to develop a comprehensive optimization strategy which considers these factors along with the subjective requirements of the customer.