Calculation of blast hole charge amount based on three-dimensional solid model of blasting rock mass

The development and use of intelligent drilling rigs make it available to obtain accurate lithology data of blast drilling. In order to make full use of drilling data to improve blasting efficiency, the following research was carried out. First, a database is established to manage and store the blast hole data recognized by the intelligent drill. Secondly, the blast hole lithology data is taken as a sample, and the inverse distance square method is used to interpolate the blasting range's solid elements to generate a three-dimensional solid model of the blasting rock mass. Afterward, the blasting range polygon and stope triangle grid are used successively in the solid model to obtain the cut 3D solid model of the blasting rock mass; finally, the blast hole charge is calculated based on the cut 3D solid model of the blasting rock. The C++ programming language is used to realize all the blast hole charge amount processes based on the three-dimensional solid model of the blasting rock mass. With the application example of No. 918 bench blasting of Shengli Open-pit Coal Mine in Xilinhot, Inner Mongolia, the blast hole charge amount in the blasting area is calculated and compared with the results of single hole rock property calculation, the results show that the blast hole charge calculated by three-dimensional rock mass model can be effectively reduced.

PEMBUATAN JIG PROSES PRE DRILL MODEL B74 GUNA MENURUNKAN REJECT CONCENTRIC PADA LINI PRODUKSI PENGECORAN OUTER TUBE DI PT KAYABA INDONESIA

Salah satu produk PT Kayaba Indonesia adalah front fork assy yang mana didalamnya terdapat part yaitu outer tube. Proses awal pembuatan outer tube adalah proses pengecoran. Ada 2 macam mesin pengecoran gravitasi yang digunakan oleh PT Kayaba Indonesia yaitu mesin pengecoran gravitasi existing tipe core dan mesin pengecoran gravitasi tilting tipe solid. Model B74 salah satu produk yang menggunakan mesin pengecoran gravitasi tilting sehingga model B74 termasuk ke dalam tipe solid. Sebelum masuk ke proses machining, outer tube model B74 harus melewati proses Pre drill untuk membuat diameter dalam agar memudahkan proses selanjutnya pada lini pemesinan. Saat ini proses Pre drill model B74 memiliki masalah reject concentric yang cukup tinggi, yaitu 7%. Proses penurunkan reject concentric proses Pre-drill model B74 telah dilakukan Penulis bersama tim mekanik proses pengecoran meliputi upaya memindahkan proses Pre-drill model B74 ke mesin macod dan pembuatan jig untuk mendukung proses tersebut. Perbaikan yang dilakukan berhasil menurunkan reject yang terjadi, dari 7% dari 8.812 set menjadi 1,4% dari 3.360 set. Selain itu perbaikan ini juga menaikan kuantitas produksi sehingga yang awalnya membutuhkan 2 shift untuk mencapai target menjadi cukup hanya 1 shift dengan hari kerja normal.

Establishing 3D hydrogeological solid model and database for sustainable groundwater management in the Vietnam Mekong delta

The Vietnam Mekong delta (VMD) is a tide-dominated delta formed by the Mekong river system. The sediments are dominantly fine grained and were deposited in the receiving basin with slight inclination of pre-existing deposits in the East sea and gulf of Thailand. The VMD is homeland to about 18 million people that exploit about 4-6 million m3/day of groundwater mainly for domestic use. In recent years, significant groundwater depletion has been occurring in many parts of the VMD due to excessive pumping. Consequently, the VMD has become increasingly faced with serious land subsidence, salt groundwater intrusion, and contamination. Establishing a 3D hydrogeological solid model and database are sorely needed to achieve sustainable groundwater management, and to serve as a basis for further in-depth analyses to quantify contributions from the above-mentioned hazards to current hydrogeological conditions. Therefore, a 3D hydrogeological solid model and database were built based on more than 1000 well logs available from the VMD. An areal distribution of the Holocene, Pleistocene, Pliocene, and Late Miocene subsurfaces from this 3D hydrogeological solid model and database showed zones of tectonic depression and uplift from Early Miocene - Quaternary. Also, the resulting areal distribution aquitards and aquifers thicknesses gave hints of ground saltwater intrusion and contamination.

Assessing the Viscoelasticity of Photopolymer Nanowires Using a Three-Parameter Solid Model for Bending Recovery Motion

Photopolymer nanowires prepared by two-photon polymerization direct laser writing (TPP-DLW) are the building blocks of many microstructure systems. These nanowires possess viscoelastic characteristics that define their deformations under applied forces when operated in a dynamic regime. A simple mechanical model was previously used to describe the bending recovery motion of deflected nanowire cantilevers in Newtonian liquids. The inverse problem is targeted in this work; the experimental observations are used to determine the nanowire physical characteristics. Most importantly, based on the linear three-parameter solid model, we derive explicit formulas to calculate the viscoelastic material parameters. It is shown that the effective elastic modulus of the studied nanowires is two orders of magnitude lower than measured for the bulk material. Additionally, we report on a notable effect of the surrounding aqueous glucose solution on the elasticity and the intrinsic viscosity of the studied nanowires made of Ormocomp.

TOWARDS A DIGITAL TWIN OF A STORAGE TANK USING LASER SCAN DATA

This paper proposes a methodology to automatically extract components of an oil storage tank from terrestrial laser scanning (TLS) point clouds, and subsequently to create a three-dimensional (3D) solid model of the tank for numerical simulation. The proposed method is integrated into a smart analysis layer of a digital twin platform consisting of three main layers: (1) smart analysis, (2) data storage, and (3) visualisation and user interaction. In this proposed method, primary components of the tank were automatically extracted in a consecutive order from a shell wall to roof and floor. Voxel-based RANSAC is employed to extract voxels containing point clouds of the shell wall, while a valley-peak-valley pattern based on kernel density estimation is implemented to remove outlier points within voxels representing to the shell wall and re-extract data points within voxels adjoined to the shell wall. Moreover, octree-based region growing is employed to extract a roof and floor from remaining point clouds. An experimental showed that the proposed framework successfully extracted all primary components of the tank and created a 3D solid model of the tank automatically. Resulting point clouds of the shell wall were directly used for estimating deformation and a 3D solid model was imported into finite element analysis (FEA) software to assess the tank in terms of stress-strain. The demonstration shows that TLS point clouds can play an important role in developing the digital twin of the oil storage tank.

The effect of model material properties on thermal imaging measurements

The temperature distributions arising on the surface of the solid model are investigated. A flow with a shock wave and laminar boundary layer interaction is considered as the main flow. Calculations of the conjugate problem are performed based on RANS approach. The investigated cases correspond to homogeneous material of the solid model and the model consisting of two materials with different thermal conductivity. In this study, the model designs are found to obtain a temperature distribution suitable for thermal imaging measurements. In addition, in the calculations, the effect of forced heating of the model wall on the temperature distribution is investigated.

Hybrid Reconstruction and Evaluation of 3D Model of Equipment Parts for Virtual Maintenance System

The research and application of reverse engineering technology are more and more extensive, but its process is still not fully mature. Aiming at the complexity of equipment parts and the diversity of accuracy requirements, the method of hybrid reconstruction and evaluation of 3D model of equipment parts for virtual maintenance system is illustrated. The general process is given. Taking the two-stage bevel gear worm reducer as the research object, the research on three-dimensional scanning, data processing and model reconstruction is carried out. This paper focuses on the reconstruction process and methods such as regional division, solid model construction based on maximum outer contour, creation of basic surface, patch fitting and so on by taking the bevel gear in the reducer as an example. Finally, 3D comparison, 2D comparison, cross-section accuracy and size of the reconstructed solid model are evaluated. The results show that the hybrid reconstruction method has strong adaptability and high efficiency. Reverse modeling and forward design are organically combined to give full play to their advantages, and the hybrid reconstruction method can effectively reverse the original design intention of the product and improve the parameterization ability of reverse modeling. It can meet the requirements of different precision models developed by virtual maintenance system, structural wall chart and atlas, multimedia and so on.