Automated design of sheet metal punches for bending multiple parts in a single setup
Sheet metal bending is a process in which bends are formed using a combination of a punch and a die. A very large number of mechanical products such as furniture panels, shelves, cabinets, housing for electro-mechanical devices, etc. are created by using the sheet metal bending process. Bending tools need to satisfy the following two criteria: (1) tools should be able to withstand bending forces, and (2) tool shapes should be such that there is no tool-part interference. In this paper, we describe a methodology for automatically designing shapes of bending punches for bending multiple parts in a single setup. We create parametric geometric models of punches. These parametric models describe the family of possible punch shapes. Using the part geometry and parametric punch shape models, we automatically generated constraints on tool parameters that eliminate the possibility of part-tool interference. We use mixed-integer techniques to identify parameters of punch shapes that result in the maximum punch strength. Finally, we perform strength analysis of the designed punch shape using "nite element analysis methods, to verify that the designed punch shape is capable of withstanding the bending forces. 2001 Elsevier Science Ltd. All rights reserved.
Sheet metal bending: Forming part families for generating shared press-brake setups
Sheet metal bending press brakes can be set up to produce more than one type of part without requiring a setup change. To exploit this flexibility, setup planning techniques are needed so that press-brake setups can be shared among many different parts. This paper describes algorithms for partitioning a given set of parts into setup-compatible part families that can be produced on the same setup. First is presented a greedy algorithm to form a part family using a bottom-up approach that makes use of the mixed-integer linear programming formulation for generating shared setups for each part family. Second is presented a mixed-integer linear programming formulation to generate a shared setup for a given set of parts if such a setup exists. By producing many different types of parts on the same setup, it is expected that there will be significant reductions in the number of setup operations, improved machine tool utilization, and more cost-effective small-batch manufacturing.
Using Infrared Thermography to Detect Moisture in Historic Masonry: A Case Study in Indiana
Nondestructive testing mapped water infiltration in the decoratively painted interior of a Masonic Temple in Muncie, Indiana.