Numerical simulation of strain localization and damage evolution in large plastic deformation using mixed finite element method

An investigation of computer simulation is presented to analyze the effects of strain localization and damage evolution in large plastic deformation. The simulation is carried out by using an elastic-plastic-damage coupling finite element program that is developed based on the concept of mixed interpolation of displacement/pressure. This program has been incorporated into a damage mechanics model as well as the corresponding damage criterion. To illustrate the performance of the proposed approach, a typical strain localization problem has been simulated. The results show that the proposed approach is of good capability to capture strain localization and predict the damage evolution.     

Improvement of copper–molybdenum ore beneficiation using a combined flotation and biohydrometallurgy method

The authors present the results of analysis of material composition and experimental investigations of acid and biohydrometallurgical leaching of middlings on grain size, pH level, leaching process duration, temperature and slurry density. The rational parameters of flotation and acid-bacterial leaching of middlings providing an efficient release of valuable components from mineral complexes and recovery to flotation concentrate and leaching solution have been determined. A combined flowsheet and a beneficiation process for bulk flotation middlings of copper–molybdenum ore have been suggested, which include middlings grinding, sulfide minerals flotation, bacterial leaching of sulfide flotation tailings, liquid-phase extraction of dissolved copper and electrolysis of re-extraction eluates. The suggested combined method of cleaning of middlings of copper–molybdenum ores beneficiation provides the total copper recovery increase by 0.8% with a reduction of the cost price of saleable material by 0.5%.     

Random dynamic analysis of vertical train–bridge systems under small probability by surrogate model and subset simulation with splitting

Railway Engineering Science - The response of the train–bridge system has an obvious random behavior. A high traffic density and a long maintenance period of a track will result in a...     

Experiment and simulation on the pyrite removal from the recirculating load of pulverizer with a dilute phase gas–solid fluidized bed

In order to reduce the energy consumption and subsequent air pollution of coal-fired power station, based on the analysis to size and density distribution of particles from the recirculating load of the classifier of pulverizer, the separation experiment on sampling material from power plant with a dilute phase fluidized bed to remove pyrite and other minerals and numerical simulation on the separation process were done. The results show that the minimum fluidization velocity is 1.62 cm/s. Pyrite and other minerals in the material are separated. Ash of the upper and bottom layer material account for 33.34% and 73.42% respectively and sulfur content occupy 1.12% and 8.96% respectively. Scanning electron microscopy and spectroscopy tests show that sulfur in the bottom material exist in the form of pyrite. Numerical simulation on the flow field form of the dilute phase separation bed with gas–solid two phase and particle motion verifies the experimental results.