Error modelling–based machining sequence optimization of a pocketed beam milling: part A, end supported beam

This paper, on the basis of error modelling, proved the optimal pocket machining sequences of a simply end supported pocketed beam using mathematic induction method. The optimal pocket machining sequence with the minimum pocket floor height error is the machining from both ends to the middle and the optimal sequence is not unique because of the symmetric supports about the central plane; meanwhile, the optimal pocket machining sequence with the minimum wall position error is the machining from the fixed end to the free end and the optimal machining sequence is unique. A beam of Al7075 (744 mm in length, 172 mm in width, and 100 in thickness ) with 9 pockets was used to demonstrate the optimal sequences. One of the optimal sequence with minimum floor height error was used in pocketing (roughing), and the maximum distortion was 0.693 mm in the middle and the maximum floor height error appeared on both sides rather than the middle, which were 0.477 mm and 0.388 mm, and part growth produced maximum wall position error was 0.719 mm. On the same part, further demonstrated the optimal sequence with minimum wall position error in finishing (with 1 mm dimension in stock for all surfaces) and the wall position errors were fully removed. The pocketed beam machining is a typical and representative case and the results and conclusion can be extended to pocketed plate/board machining and even surfacing.

Analysis and Experimental Research on Test Method of Initial Guidance Thrust

With the gradual development of aerospace industry, the demand for missile performance is also growing. The steering gear, as one of the main implementing agencies of the missile guidance and control system, can adjust the actual thrust size through the closed-loop control system during missile guidance the deflection angle of the rudder surface, in order to change the missile's flight speed and flight attitude. The missile during the flight attitude correction and speed adjustment are through the electric servo output power to change the size of the output to complete. In this paper, the unsteady turbulent analysis theory is used to analyze the thrust test mechanism of jet. Through the simulation of the flow field, the influence of bearing wall position on the impact jet backflow zone location is studied, and the position of the bearing wall whose pressure value is the closest to the true value is determined. In addition, a simplified test system of jet thrust test was designed. The relationship between wall position and pressure was verified through experiments, which verified the accuracy of simulation results.

Analisis Perkuatan Timbunan Di Atas Tanah Lunak Menggunakan Dinding Turap dengan Pendekatan Model Numerik

Embankment on soft clay may be affect settlement at subgrade, causing lateral deformation and vertical deformation around embankment. Therefore, reinforcement is needed to overcome the effects caused of the embankment. This research was conducted to find out the influence of sheet pile wall of embankment using PLAXIS 2D program based the finite element method. The analysis was done by varying of two condition, they are installation of sheet pile wall under the embankment and the sheet pile wall outside embankment. Sheet pile wall installation is carried out before embankment construction and length of sheet pile wall in this model is 15 m. The soil layers beneath the embankment consist of 10 m layer of soft clay layer and 5 m of sand layer. The height of embankment in this analysis is 8 m, where the constructing of the embankment was done in stages. The distance of sheet pile wall position under embankment from toe of embankment are -9 m, -6 m, -3 m, 0 m, 3 m dan 6 m. The results of analysis show the effective position for displacement are toe of embankment. The Installation of sheet pile walls below the embankment will reducing deformation up to 78% and the safety factor will increase up to 10%.

Algoritma Fisher-Yates Shuffle dan Flood Fill sebagai Maze Generator pada Game Labirin

Maze game is an interesting game and used to spend time. However, in the maze game, the level used forthis game still uses static levels. Static levels make the maze shape stay the same if we play the same level. Thus, players will quickly feel bored because it finds the same complexity. Maze generator is a static level problem solution on the maze game. This research uses Fisher-Yates Shuffle algorithm and Flood Fill algorithm to make maze generator. Fisher-Yates Shuffle algorithm is used for wall position randomization and Flood Fill algorithm to keep the maze results to remain resolved. The results of the application implementation yielded 30 mazes and were tested using the Hamming Distance algorithm, yielding that the result of the maze formed is always different. The average percentage rate difference produced 48% each time the maze was formed. The results of the maze that was formed performed perfect maze checking with the result of 83.33% percentage. Index Terms— Fisher-Yates Shuffle, Flood Fill, MazeGenerator, Hamming Distance