The unique behaviour of carbonate materials under shear loading has stimulated in investigating of their geological and engineering properties.Carbonate soils composed of calcium or other carbonates and most abundant in tropical marine environments are of interest from geotechnical view, especially for offshore engineers engaged with Fossil-based fuel exploitation. This was initiated in the early 1960's, when the first offshore borings in the Persian Gulf identified layers of calcarenite and thick layers of sand containing visible shell fragments.For the purpose of exploiting gas and oil resources in hot and temperate climates (e.g. Persian Gulf) off-shore structures have been placed on carbonate soils. The carbonate sediments are high crushable compared with low crushable sediments such as quartzic soils.To examine the crushability of these problematic sediments a series of monotonic compression, extension and post-cyclic triaxial tests under different densities and confining pressures was carried out to study the CRUSHING behaviour of "Rock" carbonate sand obtained from Cornwall, England.It was shown that CRUSHING coefficient decreases with increasing in maximum principal effective stress ratio for both loose and dense states. It seems that for skeletal carbonate sand maximum and minimum dry densities will be changed during shearing loading. In other words, even though the sample has experienced an increase in density, it may also have experienced a reduction in relative density.

The demand for aggregates for civil engineering construction is high in the market. The broad adoption of fly ash for producing fly ash aggregate is the best sustainable solution to fulfill aggregate demand and utilization of unused fly ash. CRUSHING is an essential step for producing angular-shaped aggregate. In this paper, an experimental study using a laboratory-scaled impact crusher was carried out to investigate the effect of CRUSHING process parameters (feed block size, crusher speed and outlet sieve size) on the quality (particle size distribution, flakiness-elongation index and mechanical properties) of angular-shaped fly ash aggregates produced after CRUSHING high-strength fly ash blocks. Particle size distribution and flakiness-elongation index were found to be changed with CRUSHING parameters. Higher CRUSHING speed resulted in small-size fly ash aggregates. Better particle size distribution of crushed fly ash aggregate was produced using a 60 mm outlet sieve compared to a 30 mm one. Well-graded fly ash aggregates with good particle shape (less flaky and less elongated) for the subbase layer of the road were obtained after CRUSHING fly ash blocks of one-third feed size in a laboratory-scaled impact crusher at a CRUSHING speed of 527 rpm and an outlet sieve of 60 mm. Mechanical properties (impact, CRUSHING and abrasion values) of the fly ash aggregate were not much affected by CRUSHING process parameters. The findings of this study will help in optimizing the CRUSHING operation of the industrial impact crusher to produce high-quality angular-shaped fly ash aggregate on a large scale.

Honeycombs are used in many industries due to their individual properties such as energy absorption property. In this paper the "angle element" is introduced and its energy dissipation mechanisms under quasi-static loading are studied. The CRUSHING load of honeycomb is calculated by energy method and describing Wierzbicki model for determining the mean CRUSHING strength and half wavelength of folding of cell walls, a new model is presented which predicts better results than the Wierzbicki model. Based on this analysis the cell geometry has important role on mechanical behavior of honeycomb structures; so that decreasing the cell size increases the mean CRUSHING strength and decreases the half wavelength of folding. On the other hand increasing the cell wall thickness increases these two parameters. The results of the new model are in good agreement with available experimental data.

Thin-walled structures have been extensively usedas energy absorbers in automobile and aerospace industries.This paper treats the collapse behaviour and energy absorption response of brass cylindrical tubes subjected to axial loading, using experiment and non-linear finite element models. In experimental approach, brass cylindrical samples were made by the process of extrusion. These samples are compressed between two rigid platens under quasi-static loading conditions and the collapse mechanism, the variations of CRUSHING load and absorbed energy are determined. A numerical model is presented based on finite element analysis to simulate the collapse process considering the non-linear responses due to material behaviour, contact and large deformation. The comparison of numerical and experimental results showed that the present model provides an appropriate procedure to determine the collapse mechanism, CRUSHING load and the amount of energy absorption. Numerical simulation techniques validated are used to carry out a parametric study of brass cylindrical tubes. In the following, influence of important parameters such as geometry imperfection (wall thickness gradient and wave formation), boundary condition, semi-apical angle, multi-cell columns reinforace and velocity impact was investigated. The results of this paper highlight the advantages of using brasscylindrical tubes as energy absorber.

In most engineering structures the energy absorption systems are used to prevent or reduce damages. In this paper, performance of a CRUSHING element of ER24PC locomotive is investigated. The numerical modeling of this CRUSHING element, after introducing its operation, is performed using the Abaqus finite element software in order to evaluate its CRUSHING characteristics. Since the shape of CRUSHING element of ER24PC locomotive is tapered, an analytical solution has been used to validate the numerical results. Because of the thickness of CRUSHING element, rupture may be occur in this element and using of a proper damage model is essential in order to simulate this rupture. From three damage models introduced in this paper, one damage model is already provided in Abaqus and the other two models have been coded. By comparing numerical results with experimental test results, proper damage model in software is developed and used in order to properly simulate the crashing process of considered element. The desirable damage model is verified by using ECE R66 standard. Finally in order to improve the energy absorption capacity metallic foam is used as a filler in energy absorber element. Through comparing the energy absorption behavior of foam filled CRUSHING element with the non-filled element the foam performance in CRUSHING element is evaluated.

The paper discusses all different types of folding mechanism in honycomb structures. A new folding mechanism named Mixed Mechanism is introduced for determining the crashing strength of hexagonal cell honeycombs subjected to axial quasi-static loading. The theoretical solution has been compared with experimental results published in literatures and an excellent correlation has been obtained. This solution can replace the less accurate earlier analysis of the same problem due to Wierzbicki.

In this paper CRUSHING of honeycomb panels subjected to impact of cylindrical projectiles is i studied and the minimum velocity of projectile required for densification of panel is analytically determined. This study shows that the minimum impact velocity needed for panel densification is directly proportional to the cell wall thickness, the panel thickness and compressive yield strength of honeycomb material; and is inversely proportional to the cell size and projectile's mass. These results are in good agreement with the available experimental data.

One of the most important structural components of engine compartment assembly in a car body is the S-rail. S-rails has significant role in absorbing energy during crash events and therefore it is designed for efficient behavior in such conditions. Driving the peak CRUSHING force of the S-rails is one of the important objectives in the design process of such structures. Peak CRUSHING force is exactly the force applied to the downstream components and then will be transferred to the cabin of vehicle. In this paper, closed form solution is performed to drive the peak CRUSHING force of the S-rails. Results of such analytical model finally are compared with the results of finite element simulation. Good agreement between such results shows the accuracy of the proposed analytical model.

In this paper, a novel approach is proposed to investigate the progressive collapse damage of prismatic thin walled metal columns with different regular cross sections, under the action of axial quasi-static and impact loads. The present work mainly focuses on implementation of some important factors which have been neglected in other studies. These factors include the effect of reducing impactor velocity and inertia effect during collapse, a mixed collapse mode for CRUSHING mechanism, and consideration of a realistic elasto-plastic model for material. Taking all these factors into account, the analysis led to some parametric algebraic equations without a possible general solution in terms of collapse variables. Consequently, a new theoretical approach was proposed based on previously offered Super Folding Element (SFE) theory, to obtain the closed form explicit relations for the static and dynamic mean CRUSHING forces and collapse variables. The proposed approach considers an analytic-numeric discretization procedure to solve these equations. To evaluate the results, a detailed finite element analysis on square mild steel models was conducted under an axial impact load, using LS-DYNA and ANSYS software programs. Comparison of the experimental results that are available in the literature with those of finite element analysis, shows the applicability of this approach in predicting the collapse behavior in such structures.

Many research studies have been conducted on the liberation of locked minerals using a crusher and comparing this device with the other devices. This paper reviews the liberation of middle coal by different methods of CRUSHING force. In the Tabas coal washing plant, particles of 0.5-50 mm size are processed through the heavy media method (using 3 Tri-flo separators) and particles of 0-0.5 mm size are processed using the flotation method (using 6 column flotation cells). A Tri-flo separator with a diameter of 700 mm and the capacity of 120 tons per hour is used for the cleaning of 6-50 mm raw coal particles. The study was conducted using a laboratory jaw crusher and a cage mill with a specific comminution ratio, both CRUSHING forces were analyzed with the same distribution and mechanism of production of fines. In this study, grading and washability characteristics of a representative sample of middle product were reviewed and the dimensions of the ash were measured for each section. Intermediate product CRUSHING using a laboratory jaw crusher and an industrial cage mill were conducted at up to 5 mm size and 50 percent of final speed. The amount of coal released after each section grading was determined by a sinking and floating test for size +0.5 mm and release analysis and ash testing for smaller dimensions of -0.5, these tests were conducted for each section product dimension. The results indicated that utilizing a cage mill is more effective than a laboratory jaw crusher, resulting in 11-percent more yield with 12 ash. The rate of fines produced through the laboratory jaw crusher is less than the industrial cage mill.