Reconfigurable fixture locating layout for compliant sheet metal welded assemblies subjected to welding force variations

Abstract

Reconfigurable sheet metal fixtures are used to assemble sheet metal product families of similar locating layouts. These have to maintain locating and clamping layout fidelity for the entire range of a product family. Locating and clamping regions of a sheet metal part tend to dislocate and distort once subjected to nonequalized resistance spot welding guns. The resulted working regions are different in location and size from the original ones. In this article, Monte Carlo simulations are used by the authors to investigate the expected size and location of the working regions of parts in a sheet metal family subjected to random resistance spot welding forces. In the case study, proposed methodology is applied to an available automobile underbody floor panel family. Resulted working regions after the probabilistic deflection analysis are different from the initial ones both in size and location. The results show that by incorporating the random nonequalized clamping forces, the size of the working regions for fixturing elements is increased. Also, the possibility of designing a fixture that cannot assemble the full range of parts is reduced.

Research on the optimal design technology of a digital assembly sequence based on an internet of things data collection framework

“…Comparison between the ant colony algorithm, the genetic algorithm and the artificial fish swarm algorithm for the assembly disassembly sequence optimization design First, in order to analyse the efficiency of the ant colony algorithm compared to the fish swarm algorithm during for a simple data environment, this paper uses the assembly case of a machine tool modular fixture, as previously described, [35][36][37][38][39] to verify the accuracy and efficiency of the ant colony algorithm compared with genetic algorithm (The assembly design of a complex controller as shown in Figure 5, and the tools list for the controller assembly is shown in Table 4). Therefore, the calculation results of the two algorithms are obtained, when the assembly process is complex and more parts are assembled (as shown in Figures 6 and 7).…”

Sheet-metal bend sequence planning subjected to process and material variations

“…Faraz et al utilized Monte Carlo simulations to compute the optimum working regions for sheet-metal welding fixtures. Simulations were performed to evaluate the expected locating and clamping regions based on the statistical data of a manufacturing setup [8]. Rui et al performed a review of the research in the field of NC press-brake sheet-metal bending process planning.…”

“…It can be observed that bends (2,3,4) and (6,7,8) can be combined depending upon the capability of a particular pressbrake and the availability of necessary tooling. If after preprocessing it is decided that manufacturing facility capability allows combining the respective bends then the bends required to form the part will reduce to six as shown in Fig.…”

“…Nominal flange lengths and base length selected for the part are 30 and 50 mm respectively. By utilizing the assumptions made at the start it can be seen that bends (4,7,10) and (2,5,8) can be combined respectively which result into a reduction of the total number of bends from 10 to 6 as shown in the developed blank in Fig. 7c.…”