Design and implementation of a measuring system for shipbuilding based on WinCE
The measurement in shipbuilding is an important task of improving the quality and efficiency. Precision industrial surveying and computer technology can be applied to embedded measurement systems, in which the convenient functions of coordinate data collection, assistant calculation and analysis are provided to test shipbuilding quality. In this paper, the process of system design and operation was described in detail, and then the key technologies involved were discussed.
Applications of Lodrigues matrix in 3D coordinate transformation
Three transformation models (Bursa-Wolf, Molodensky, and WTUSM) are generally used between two data systems transformation. The linear models are used when the rotation angles are small; however, when the rotation angles get bigger, model errors will be produced. In this paper, we present a method with three main terms: the traditional ➀ rotation angles θ, φ, ψ are substituted with a,b,c which are three respective values in the anti-symmetrical or Lodrigues matrix; ➁ directly and accurately calculating the formula of seven parameters in any value of rotation angles; and ➂ a corresponding adjustment model is established. This method does not use the triangle function. Instead it uses addition, subtraction, multiplication and division, and the complexity of the equation is reduced, making the calculation easy and quick.
Flow and Compaction During the Vacuum Assisted Resin Transfer Molding Process
The flow of an epoxy resin and compaction behavior of carbon fiber preform during vacuum- assisted resin transfer molding (VARTM) infiltration was measured using an instrumented tool. Composite panels were fabricated by the VARTM process using SAERTEX(R)2 multi-axial non- crimp carbon fiber fabric and the A.T.A.R.D. SI-ZG-5A epoxy resin. Resin pressure and preform thickness variation was measured during infiltration. The effects of the resin on the compaction behavior of the preform were measured. The local preform compaction during the infiltration is a combination of wetting and spring-back deformations. Flow front position computed by the 3DINFIL model was compared with the experimental data.