Computation of limit and shakedown using the NS-FEM and second-order cone programming

This paper presents a novel numerical procedure for computation of limit and shakedown using node-based smoothed finite element method (NS-FEM) in combination with second-order cone programming (SOCP). The obtained discretization formulation is then cast in a form which involves second-order cone constraints, ensuring that the underlying optimization problem can be solved by highly efficient primal-dual interior point algorithm. Furthermore, in the NS-FEM, the system stiffness matrix is computed using the smoothed strains over the smoothing domains associated with nodes. This ensures that the size of the resulting optimization problem is kept to a minimum. The efficiency of the present approach is illustrated by examining several numerical examples

An XFEM based kinematic limit analysis formulation for plane strain cracked structures using SOCP

This paper extends a numerical procedure for limit analysis based on extended finite element method (XFEM) and second-order cone programming (SOCP) to plane strain cracked structures. The cracked structures are easily modelled and simulated using XFEM because it allows discontinuities across elements, and these discontinuities are recognized by means of level set method. The resulting discretization formulation is then cast in a form which involves second-order cone constraints, ensuring that the underlying optimization problem can be solved by highly efficient primal-dual interior point algorithm. The efficiency of the present approach is illustrated by examing several numerical examples

The Potential of the Rice Value Chain in the Mekong Delta to Develop High Value Export Markets

This study aims at analyzing the current status of the rice value chain in the Mekong Delta focusing on export channels. The study assessed primary data collected from respondents related to the chain in the year 2020. Research results show that about 35% of rice in the region is used for export, of which most of the rice exported belongs to the high quality segment. Although improvements achieved recently, the regional rice value chain still faces many limitations. The study proposes solutions to strengthen the rice value chain and increase the volume of high quality rice exported into more demanding high income markets

Dielectrophoresis can control the density of CNT membranes as confirmed by experiment and dissipative particle simulation

In forests and membranes, Carbon nano tubes (CNT) are not individual, instead they tend to be agglomerated into bundles because of the strong van der Waals interaction. CNTs usually form into bundles containing up to hundreds or thousands of parallel CNTs named as fibres which create networks within a CNT membrane. Recently, CNT based macrostructures (yarn and membrane) have increasingly been used in various applications in electronics, medical and bioengineering. Meanwhile the volume density of CNTs impacts on mechanical and physical properties of macrostructures, the controlling of the density of membranes is very complex. Thus, in this paper, an electric processing to dilate CNT membrane is sufficiently studied and investigated by both the experiment and particle based numerical simulation. Several initially potential applications of the method are also represented not only to control the density of CNTs but also to improve the CNTs’ alignment in macro-structures

Liquid pumping and mixing by PZT synthetic jet

In this paper, a PZT synthetic jet that can function as both an efficient pumping and mixing device is developed. Compare with the conventional design where the practice of controlling the internal flow is undertaken by microvalves structure, this approach promotes the durability and allows the device to work with different liquids at high Reynold number without losing of backflow from the diffuser, therefore provides efficient mixing. The pumping performance is applicable for commercialized counterparts while the homogeneous medium was obtained at downstream in the experiments, which was further confirmed by simulation. Notably, the chaotic mixing feature of the device is also applicable for immiscible liquids with the micro-droplet formation result at the outlet