Papers by Keyword: Consolidation

Abstract: Thermoforming of thermoplastic fiber-reinforced composites enables cost-effective production of complex, high-volume components, yet wrinkling and shear-induced thickness variations remain persistent challenges in compound-curvature geometries, often leading to nonuniform consolidation. This work presents a predictive virtual process simulation that integrates discrete mesoscopic finite element modeling with targeted blank design strategies to address these limitations. The approach, developed by the Sherwood Group and implemented in LS-DYNA, is applied to the thermoforming of a UHMWPE unidirectional cross-ply composite system (DSM® Dyneema® HB210). A thickness-stretch shell formulation (SHELL ELFORM25), coupled with a user-defined material model, is employed to simultaneously capture in-plane shear, through-thickness deformation, and frictional interactions during forming. A parametric study is conducted to evaluate the combined effects of tooling geometry and strategically introduced slits in the blank, including side-and corner-oriented configurations. The results demonstrate that the proposed formulation provides an effective balance between computational efficiency and predictive accuracy while explicitly reducing shear-induced thickening. Notably, corner-oriented slits at 45° to the fiber directions significantly reduced thickness variability and wrinkle severity compared to unmodified blanks and side-slit configurations. These findings highlight the novelty of integrating thickness-aware forming simulations with geometric blank modification as a robust pathway for achieving near-uniform thickness and improved preform quality in thermoformed composite parts.

Abstract: Desert soils present some issues that need improvement. Some of these are high permeability and collapsibility potential. These problems are due to the uniform particle size distribution and the lack of particle edges. Soil improvement is required to mitigate these issues. Cement is widely used for soil stabilization but has environmental issues since it is a significant source of CO₂ emissions and requires high energy consumption. In this study, the calcined shale material is utilized as a partial replacement for cement to reduce the permeability and compressibility of soils more sustainably. The study considers three cement doses of 5%, 10%, and 15% and four calcined shale percentages of 10, 30, 50, and 70%. A series of falling head permeability and one-dimensional consolidation tests were conducted to examine the performance of cement and calcined shale as stabilizers. The results of the study indicate that the addition of 30% calcined shale as a partial replacement of cement has the most significant effect on the conductivity and compressibility of the soils. An increase in cement content decreases the permeability and compressibility of the soil due to the hydration of cement. Conversely, the conductivity and consolidation of the soil are initially decreased with an increase in the calcined shale up to 30% and then start to increase. In summary, this study reveals that the presence of CS and cement has a substantial effect on the conductivity and compressibility of the soils.

Abstract: The production of nanocomposite tungsten carbide buttons was studied. Using the mechanically induced solid-state mixing technique, the nanopowders were mixed with Cobalt (Co) and Zirconium Oxide (ZrO₂). During the consolidation and manufacturing process, the nanocrystalline characteristics of the nanocomposite were improved by replacing Co with ZrO₂-2 mol% yttria (YO₃), and the average grain size was reduced to 23-49µm. With the advent of fast sintering techniques and the synthesis of nanocomposites from the consolidation of nanocomposite powders, full dense buttons with outstanding properties were produced. These buttons have a very high nano hardness value (24.41GPa) and a low Young's modulus (E) value (332.02 GPa).

Abstract: The most of limestone objects in museums, storehouses and archaeological sites suffered from fragility and weakness which lead to the degradation of these artifacts. The present paper aims to evaluate the use of some nanolime-silica core-shell for consolidation process of these weak limestone artifacts. Two concentrations (5% and 10% w/w) were prepared for consolidating the aged limestone cubic samples. After complete drying, the cubic stones were exposed to the accelerated heat aging. The evaluation of consolidation process for the treated and aged treated samples was performed by some analytical methods such as measurement of physical properties and compressive strength. While, the investigation of surface morphology was carried out by scanning electron microscope (SEM) and measurement of contact angle. The characterization process for the prepared core-shell showed the smoothness and spherical shape of the grains with approximate size of 72 nm. The results of physical properties revealed that the treated samples with 10% of nanolime-silica core-shell gave the lowest porosity (15.57%) and water absorption (6.26%). Additionally, the treated samples with 10% concentration of nanolime-silica core-shell gave the highest values of compressive strength (21.23 Cm²/ Kg) and contact angle (122.78°). Moreover, the investigation using SEM revealed that the smoothness and good penetration for the treated sample with 10% concentration of nanolime-silica core-shell. The results of the present study revealed that the efficiency of consolidation process was maximum using 10% concentration of nanolime-silica core-shell and hence it was applied for consolidation of an archaeological limestone octagonal column, Egypt.

Abstract: The technological process of thin-film sputtering significantly depends on the quality of the target for magnetron sputtering. This paper presents the features of obtaining the multicomponent magnetron target for the formation of non-porous transformation-hardenable coatings by the method of impact electric pulse consolidation. Special considerartion is given to the blend preparation and technological parameters of compaction. Blend powder consolidation under impact electric pulse compaction at different speeds of the striker has been investigated. At high speeds of the drop-hammer striker, the time parameters of the dynamic impact and electric pulse heating of the powder billet are shown to superpose, which leads to the final consolidation of the ceramic blend of the target for magnetron sputtering. The use of the technology of impact electric pulse compaction has made it possible to obtain multicomponent magnetron targets for formation of non-porous transformation-hardenable coatings of a given composition.

Abstract: This paper presents the compression and consolidation behaviors of clay supported by soil-cement column. A series of consolidation tests was performed on kaolin samples supported by soil-cement column with the ratio between diameters of column and soil sample () ranging from 0 to 0.4. All samples with soil-cement column were cured for 28 days under the vertical pressure of 25 kPa. The sample preparation techniques simulating dry deep soil mixing method was developed. The test results showed the elastic region expanded with increasing value of . However, there was no effect of on deformation behavior in the elasto-plastic region. Moreover, the value of was considered constant over the range of testing stress level, for the value of of 0 and 0.2. For the value of of 0.3 and 0.4, the values of in the elastic region was greater than that in elasto-plastic region.

Abstract: The purpose of this study is to discuss which constitutive law can describes at best the observed behavior of Silt and Gravelly Clay on the basis of experimental and analytical results. To find numerical solution for saturated soils in oedometer test Plaxis 2D the finite element software was used. In order to obtain the compressibility, excess pore pressure and degree of consolidation curves; two constitutive laws were used in this work: the Soft Soil Model ‘SSM’ and the Modified Cam Clay Model ‘MCC’. Predicted results were found in good agreement with measurements obtained from experimental test and analytical solutions. The Soft Soil is in good agreement with experimental results in the compressibility curve; however the Modified Cam Clay Model is the most appropriate if compared with the analytical solution.

Abstract: Quartzite sculptures are considered some of the most impressive and informative archaeological remains which have been found in the most of Egyptian archaeological sites. Regrettably, quartzite sculptures suffer from many deterioration aspects such as granular disintegration, scaling, cracking, efflorescence, soiling, microbiological colonization. Water is the main aggressive deterioration factor of stones and stone-based monuments, as in addition to its direct role in deterioration mechanisms, it plays as a catalyst in the physicochemical and microbiological deterioration processes.During the last two decades, polymer nanocomposites have widely been applied in the field of cultural heritage conservation due to their unique physical and chemical characteristics. Zinc oxide nanoparticles are among the most important semiconductive nanomaterials that have been applied in the fabrication of nanocomposites. They have been demonstrated to improve the physicochemical and mechanical properties of polymers. In addition, zinc oxide nanoparticles were mixed with polymers in order to fabricate superhydrophobic and self-cleaning protective materials.The aim of this paper is to evaluate the efficiency of zinc oxide nanocomposites, in order to select the best of them for the consolidation and protection of a colossal quartzite statue of Ramesses II. The properties of the treated quartzite samples were comparatively examined by colourimetric measurements, static water contact angle, compressive strength, and scanning electron microscope.

Abstract: Many mural paintings stored in museums suffer from the heavy loaded added gypsum layers to the background. Currently anew way will be used for support the back ground of mural painting using the nanocalcium hydroxide which added to the background of it. This nanomaterial is smoothly penetrate inside the mural painting structure then it combines with CO₂ producing CaCO₃ the original binder in all mural paintings especially fresco paintings, The mechanical characteristics were tested to determine the change in properties of the interior structure of the treated Coptic fresco painting

Abstract: Titanium is a hard metal with good mechanical properties, corrosion resistant and biocompatibility which makes it have a wide range of applications (biomedical and aerospace). Severe plastic deformation (SPD) is employed to produce Ultrafine Grained (UFG) structures. UFG structures have better mechanical properties due to their compaction. Equal Channel Angular Pressing (ECAP) is adapted to produce a UFG structure in Titanium. In this process, titanium sponge powder is filled in the aluminium shell by intermediate tapping to fill the volume of the shell. The shell is then closed with an Al cap and ECAP is done with continuous back pressure at 300°C. The test specimen has undergone four passes in route B_C at different back pressure (50, 100 and 150 MPa) where titanium is consolidated without any crack. Titanium showed decreased grain size and porosity with increasing backpressure. In particular, it is seen that the sample ECAPed by 100 MPa backpressure showed a relative density of about 98% with a hardness of 37 HRC. It is seen that ECAP is more economical and the product obtained by the ECAP process has better properties.