A Designer-Driven Welding Simulation Analysis to Define the Best Weld Sequence for Panel Structures

Author(s):  
Mahyar Asadi ◽  
Majid Tanbakuei Kashani ◽  
Mohammad Mohseni ◽  
Mathew Smith

Distortion is a common problem in welded panel structures, historically techniques to mitigate this problem have been developed empirically. A usual approach involves defining an intermittent weld sequence, a process that is extremely difficult to optimize given the large number of possible combinations i.e. hundreds or even thousands for multi-pass welds. Typically, plans to control weld distortion are therefore largely intuitive with welding engineers relying on their experience combined with the results of a limited number of practical tests. However, with modern computing, welding engineers can now include all the physics of welding in a simulation allowing them to cheaply and efficiently optimize a welding sequence without the need for multiple physical samples. The final welding procedure is then physically qualified based on the simulation results. In this paper, the authors present their use of computer modeling to automate the implementation of welding patterns to minimize distortion in panel lines. We describe a signature technique based on the Joint Rigidity Method where a combinatorial algorithm optimizes the welding sequence based on the panel’s resistance to angular bending i.e. the welding sequence starts at the point in the panel with the highest rigidity and moves progressively toward the lowest rigidity thereby minimizing distortion. This enables the designer to carry out an optimization of this complex weld design without relying on empirical observations.

Author(s):  
Mahyar Asadi ◽  
Ghazi Alsoruji

Weld sequence optimization, which is determining the best (and worst) welding sequence for welding work pieces, is a very common problem in welding design. The solution for such a combinatorial problem is limited by available resources. Although there are fast simulation models that support sequencing design, still it takes long because of many possible combinations, e.g. millions in a welded structure involving 10 passes. It is not feasible to choose the optimal sequence by evaluating all possible combinations, therefore this paper employs surrogate modeling that partially explores the design space and constructs an approximation model from some combinations of solutions of the expensive simulation model to mimic the behavior of the simulation model as closely as possible but at a much lower computational time and cost. This surrogate model, then, could be used to approximate the behavior of the other combinations and to find the best (and worst) sequence in terms of distortion. The technique is developed and tested on a simple panel structure with 4 weld passes, but essentially can be generalized to many weld passes. A comparison between the results of the surrogate model and the full transient FEM analysis all possible combinations shows the accuracy of the algorithm/model.


2021 ◽  
Author(s):  
Qiongxiao Wu ◽  
Jianjun Wang ◽  
Jingming Chen ◽  
Pengzheng Li

Abstract Based on the one-dimensional simulation model of lubricating oil system is established and analyzed by using FLOWMASTER software, this paper proposes a new method of optimizing lubricating oil system by PID technology. Ensure that the configuration requirements and control strategies of the relevant accessories of the simulation model are satisfied with the design requirements. Firstly, by simulating lubricating oil pressure fluctuation and lubricating oil flow distribution under Open/Close Valve in different opening and closing time, the optimal opening/closing time of Open/Close Valve is determined to be 0.2 s and 0.5 s respectively. Secondly, by writing the controller script file combined with a controller to realize automatic unloading relief valve simulation, determine the relief valve pressure regulating range of 0∼0.38 MPa, For precision of constant pressure valve of oil spill, the simulation results show that the average 10 m3/h flow caused by pressure changes of about 0.06 MPa. Under the flow sudden change signal of about 40 m3/h, the maximum pressure change is less than 0.1 MPa. Through the simulation results, it is found that most of the lubrication parts in the original design have the phenomenon of flow redundancy, which causes unnecessary pump power loss. The system is optimized by PID technology. By comparing the simulation results before and after optimization, it is found that the speed of constant displacement pump could be changed in time by PID controller, and the flow redundancy could be improved significantly, so the lubricating oil system could be lower consumption and achieve the purpose of optimization.


Author(s):  
Yangbing Zheng ◽  
Xiao Xue ◽  
Jisong Zhang

In order to improve the fault diagnosis effectiveness of hydraulic system in erecting devices, the fuzzy neural neural network is applied to carry out fault diagnosis of hydraulic system. Firstly, the main faults of hydraulic system of erecting mechanism are summarized. The main faults of hydraulic system of erecting devices concludes abnormal noise, high temperature of hydraulic oil of hydraulic system, leakage of hydraulic system, low operating speed of hydraulic system, and the characteristics of different faults are analyzed. Secondly, basic theory of fuzzy neural network is studied, and the framework of fuzzy neural network is designed. The inputting layer, fuzzy layer, fuzzy relation layer, relationship layer after fuzzy operation and outputting layer of fuzzy neural network are designed, and the corresponding mathematical models are confirmed. The analysis procedure of fuzzy neural network is established. Thirdly, simulation analysis is carried out for a hydraulic system in erecting device, the BP neural network reaches convergence after 600 times iterations, and the fuzzy neural network reaches convergence after 400 times iterations, fuzzy neural network can obtain higher accuracy than BP neural network, and running time of fuzzy neural network is less than that of BP neural network, therefore, simulation results show that the fuzzy neural network can effectively improve the fault diagnosis efficiency and precision. Therefore, the fuzzy neural network is reliable for fault diagnosis of hydraulic system in erecting devices, which has higher fault diagnosis effect, which can provide the theory basis for healthy detection of hydraulic system in erecting devices.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Lei Xu ◽  
Ning Zhang ◽  
Liqing Fang ◽  
Huadong Chen ◽  
Pengfei Lin ◽  
...  

The magnetic gradient full-tensor measurement system is diverse, and the magnetometer array structure is complex. Aimed at the problem, seven magnetic gradient full-tensor measurement system models are studied in detail. The full-tensor measurement theories of the tensor measurement arrays are analyzed. Under the same baseline distance, the magnetic dipole model is used to simulate the measurement system. Based on different measurement systems, the paper quantitatively compares and analyzes the error of the structure. A more optimized magnetic gradient full-tensor measurement system is suggested. The simulation results show that the measurement accuracy of the planar measurement system is slightly higher than that of the stereo measurement system. Among them, the cross-shaped and square measurement systems have relatively smaller structural errors and higher measurement accuracy.


2018 ◽  
Vol 2 (2) ◽  
pp. 96-107
Author(s):  
Freddy Wangke

The purpose of the study was to determine the effect of increasing expenditure and increasing the minimum wage of the government in the simultaneous model of the industrial sector of DKI Jakarta province. The estimation model in the simultaneous model of the industrial sector of DKI province uses the 2 SLS (Two-Stage Least Squares) method. The simulation results of a 10% increase in the expenditure of the provincial government of DKI has resulted in an increase of investment of 4.72%, production growth of 0.19%, employment of 0.17%, an increase in production costs by 0.24%, and company profits increased by 0.10%. On the other hand, the simulation results of a 10% increase in the provincial minimum wage has resulted in a decrease in labor absorption by 0.55%, a decrease in production in the industrial sector has resulted in 0.21%, a decrease in investment by 0.07%, and a decrease in production costs by 0.04%.


2014 ◽  
Vol 940 ◽  
pp. 132-135 ◽  
Author(s):  
Yi Fan Zhao ◽  
Ling Sha ◽  
Yi Zhu

Established the dynamics simulation analysis model of crane hoisting mechanism based on the theory of dynamics in Adams software, and then through the three dimensional model of lifting mechanism dynamics entities, the constraints, load, drive can be added, the motion law can be defined to simulation analysis the change of the force of wire rope, the change of displacement, velocity and acceleration of lifting weight in the lifting process. On the basis of the simulation results, it can make a great improvement for the structure of crane and provide a meaningful theoretical reference for the hoisting machinery innovation design.


Author(s):  
Xiaoqin Deng ◽  
Ran Yang ◽  
Yu Niu ◽  

Space-borne gravitational wave detection imposes a demanding requirement on the sensitivity of the laser interferometer. Among all disturbances that affect the measurement accuracy of the laser interferometer, temperature fluctuations contribute significantly. In this paper, the structure model and the interference path design of Taiji-1 laser interferometer have been used to conduct a preliminary simulation analysis of the temperature fluctuation noise through the finite element method. The temperature, the displacement and the optical path difference fluctuations have been obtained and theoretically analyzed. The preliminary simulation results are consistent with the theoretical analysis, which shows that the thermal–structural–optical simulation scheme adopted in this paper is reasonable. With the preliminary simulation results and the actual temperature control of Taiji-1 laser interferometer, we estimate that in Taiji-1 laser interferometer system, the temperature fluctuation is below the order of mK, the node displacement is within [Formula: see text][Formula: see text]pm, and the interference arm length difference fluctuation amplitude of the laser interferometer is also within [Formula: see text][Formula: see text]pm.


2020 ◽  
Vol 12 (9) ◽  
pp. 168781402095780
Author(s):  
Mei Fang ◽  
Zhihong Yu ◽  
Wenjie Zhang

Throwing device is an important factor that directly affects the performance of chaff cutter. In this work, the dynamic analysis linked with the problem of low efficiency and residue blockage of disc knife chaff cutter is executed. Based on this perspective, the mathematical model, simulation, and testing of the material movement have been carried out. Simulations are performed in MATLAB/Simulink environment. An anemometer records the airflow velocity, which provides data for simulation analysis. The simulation results showed that during the movement along the blade, the material first performs deceleration and then accelerates; in other stages, only deceleration. And finally calculated the throwing distance. To support the presented simulations, an experimental study is conducted. The experimental results are compared with simulation results, the maximum relative error between the simulated value and the experimental value is 9.42%, which verified the correctness of the model. This research provides a theoretical basis for the structural design, parameter optimization, and matching of the chaff cutter.


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