Cyclic Shear Response of Fine-Sand Tailings Using Cyclic Direct Shear Test

The extraction and processing of mineral and metal ores in the mining industry comes paired with large amounts of mine waste, also known as tailings. This waste consists of various chemicals, acids, and heavy metals which are used during these extraction processes. The tailings are usually stored off in tailings storage facilities (TSF) in a...

Steel Slag Aggregate Characteristics Evaluation as Railway Ballast

The use of recycled materials is a new tendency in the field of railway engineering. Steel slag aggregates (SSA) are one of the recycled materials derived from the steel industry. The application of SSA in ballasted railway tracks requires mechanical examination. In the present paper, the shear behavior of the ballast layer constructed by SSA...

Analysis of furnace slag in railway sub-ballast based on experimental tests and DEM simulations

Under the high requirement of ballast materials and the frequent maintenance of high-speed and heavy-haul railway, the maintenance cost and material consumption become an important problem. Several methods are used to increase the stability and service life of railway structure, also using recycled materials in ballast bed construction can be a...

Replicating cohesive and stress-history-dependent behavior of bulk solids: Feasibility and definiteness in DEM calibration procedure

This paper presents a multi-step DEM calibration procedure for cohesive solid materials, incorporating feasibility in finding a non-empty solution space and definiteness in capturing bulk responses independently of calibration targets. Our procedure follows four steps: (I) feasibility; (II) screening of DEM variables; (III) surrogate modeling...

Through Package Via: A bottom-up approach

The rapid development of semiconductor industry in the past decades has reshaped the world tremendously and greatly changed people's lives. Two-dimensional (2D) down-sizing of semiconductor devices following the “Moore's law” for many years is now reaching its boundary conditions of further exponential growth and three-dimensional (3D)...

Bulk properties variability and interdependency determination for cohesive iron ore

An ideal unit of bulk transport or storage equipment is able to handle cohesive iron ore with consistent productivity. In practice, however, uncontrollable bulk property variations affect the productivity. Therefore, it is important to understand the effect of uncontrollable variations on the process. This study quantifies variability and...

One‐way shear strength of wide reinforced concrete members without stirrups

The calibration of most analytical models that assess the shear strength of wide reinforced concrete members without shear reinforcement is based on simply supported beam tests, which may not be representative of slabs and wide members failing in shear. This paper addresses the knowledge on the shear strength of wide members, identification of...

A hybrid particle-geometric scaling approach for elasto-plastic adhesive DEM contact models

The computation time of Discrete Element Method (DEM) simulations increases exponentially when particle size is reduced or the number of particles increased. This critical challenge limits the use of DEM simulation for industrial applications, such as powder flow in silos. Scaling techniques can offer a solution to reduce computation time. In...

The influence of apparatus stiffness on the results of cyclic direct simple shear tests on dense sand

A series of undrained cyclic direct simple shear (CDSS) tests on dense Toyoura sand has been performed with the aim to investigate the influence of the stiffness of the DSS device on test results. To this end, springs were installed to reduce deliberately the stiffness of the apparatus. It is shown that the cyclic resistance of the sand...

Experimental and numerical investigations on the shear behaviour of recycled railway ballast

Ballast degradation is frequently observed under cyclic loading, and results in bearing capacity and drainage problem of ballast track. To keep the stability and safety, periodical maintenances are needed, such as cleaning and replacement, which produce a huge amount of wasted ballast. Thus, reusing the deteriorated ballast can become a...

Skin friction of diaphragm walls: An experimental study based on modified direct-shear tests

This thesis aims to analyse the conservatism in the current Dutch recommendations on the external friction angle 𝛿 of diaphragm walls: 𝛿 = 𝑚𝑖𝑛[𝜙, 20°] (for curved slip surfaces) (CUR/COB, 2010), by means of an experimental investigation. Based on literature, two sources of conservatism are identified: 1) filter cake contamination by excavated...

Effect of Laboratory Repeatability of Direct Shear Test on Slope Stability

The present work quantified the laboratory geotechnical variability by repeatability direct shear test (DS) on alluvial fine-grained soils. The effect of laboratory variability of geotechnical parameters (cohesion c' and friction angle ϕ′) on slope stability was investigated. A mixture of compacted fine sand (40%) and clayey silt (60%) taken...

Surface Modification of Titanium and Polyimide Sheet for Adhesive Bonding

Major industrial sectors like automotive, aerospace and others are increasingly using polymer composites in their structural parts. Polyimide sheet and adhesives, are high performance polymers. They are widely used in various engineering applications due to their excellent thermal, mechanical and chemical properties and their resistance to...

Durability of polyimide to titanium bonds

Titanium and its alloys are usually bonded together using a high temperature resistant polyimide or epoxy adhesives. Such adhesives can withstand temperatures from 200°C to300°C. Earlier research work indicates that Surface modification of titanium with mechanical treatment and atmospheric pressure plasma treatment techniques leads to improved...

Moisture absorption analysis of high performance polyimide adhesive

The high temperature resistant polymers and metal composites are used widely in aviation, space, automotive and electronics industry. The high temperature resistant polymers and metals are joined together using high temperature adhesives. Polyimide and epoxy adhesives that can withstand high temperature (200 °C-300 °C) are commonly used for...

Surface Modification of Titanium by Atmospheric Pressure Plasma Treatment for Adhesive Bonding and Its Application to Aviation and Space

Titanium is one of the most effective materials for structural application of space craft and aviation. Titanium alloys are widely used in solid rocket booster cases, guidance control pressure vessel and other different applications demanding light weight and reliability. Aerospace industry is also a larger market for titanium products and...

Sequentially linear analysis of masonry structures under nonproportional loading

On the behaviour of rubberlike materials in compression and shear