Cylinder Compression Research Articles

Experimental and analytical studies of size effects on compressive ductility response of Ultra-High-Performance Fiber-Reinforced concrete

Ultra-high-performance fiber-reinforced concrete (UHPFRC) has gained a great deal of increasing interest in structural engineering applications, particularly where high ductility, strength, and high impact resistance are of prime concern. This study focuses primarily on the size effects ductility characteristics of UHPFRC with varying fiber concentrations subjected to uniaxial compressive load. It shows how to process the data from compression cylinder tests to extract the size-dependent strain at peak stress to provide a generic size-dependent stress–strain analytical model. For a slenderness factor of 2, the predicted peak stress from the analytical model deviated 0.34%, 0.26%, and 10.5% from the experimental peak stress results for a fiber concentration of 1%, 2%, and 3%, respectively, indicating good estimate of the analytical model with the experimental results. Furthermore, a numerical flexural segmental moment-rotation approach is applied to incorporate an analytical model to quantify apparently disparate UHPFRC member strength and ductility. Tests have shown that it is not the enhancement in the material concrete compressive strength but the phenomenal brittle ductility nature, observed as a result of increasing the slenderness of the specimen; in contrast, a substantial increase in ductility was achieved after crushing of concrete due to the addition of fibers. A size-dependent analytical approach has estimated good fit with the experimental and other published results. Finally, numerical simulation using a segmental approach at the ultimate limit state of rotation dealing with flexural ductility is significantly influenced by the increase in slenderness factor of the specimens and fiber concentrations.This is evident as the rotation capacity decreased by 62% and 75% for a slenderness factor of 3 and 4, respectively, compared to the slenderness factor 2, when the fiber concentration was 1%. Furthermore, for 2% fiber concentration, the decrease was 54%, and 80%, and for 3% fiber concentration, the decrease was found to be 49%, and 79% for the slenderness factor of 3 and 4, respectively in comparison to the slenderness factor 2, suggesting both slenderness factor and fiber concentration have a significant impact on the flexural ductility.

The study of steel wire winding split type ultrahigh pressure die based on different winding methods

ABSTRACT We propose a novel structure of ultrahigh pressure die which consists of a split compression cylinder, a support ring, and steel wire winding, and the impacts of various steel wire winding methods on the ultimate cylinder pressure-bearing capacity are investigated. The investigations are conducted on the pre-stressing dies using the equal tensile stress (ETS), equal shear stress (ESS), and constant tangential stress (CTS) winding approaches. First, it is determined theoretically what the maximum cavity pressure and the necessary number of winding layers would be. The shear stresses of the cylinder and the support ring, the displacements of the cylinder, and the axial stresses of the steel wire layer are then examined using the finite element method. The results of the theoretical calculation and simulation are compared and discussed. The findings indicate that the ESS winding is a better option.

A comparative study on the effect of nano-additives on performance and emission characteristics of CI engine run on castor biodiesel blended fuel

Biodiesel is a promising alternative fuel because of its renewable status, biodegradability, non-toxicity, and low pollution levels. However, other limitations such as high viscosity, low thermal energy content, poor atomization, greater densities, and higher (NOx) exhaust emissions hinder its adoption as a prospective diesel alternative. The current study focuses on comparing and analyzing the performance and emission effects of introducing single and hybrid cerium oxide (CeO2) and aluminum oxide (Al2O3) nanoparticles to a fuel blend of 20 % castor biodiesel and 80 % diesel (CB20) made from castor seed oil. The pulsed plasma in liquid technique, a straightforward one-step procedure, was used to create cerium oxide (CeO2) nanoparticles. When Al2O3 nanoparticles were added to the CB20, the cylinder pressure and rate of heat release increased. Therefore, in this study single and hybrid cerium oxide (CeO2) and aluminum oxide (Al2O3) nanoparticles are introduced. The tests were conducted on a single cylinder compression ignition engine at varied engine speeds between 1250 and 3200 rpm while keeping a constant engine load. Using a water bath and sonication, two concentrations of the nanoparticles—80 and 100 ppm—were introduced to the fuel blends, along with Tween 80 and span 80 surfactants to improve blend stability. Different tested fuel samples, including pure diesel CB0, CB20, CB20C100, CB20C80, CB20A100, CB20A80, CB20A40C40, and CB20A50C50, were examined for their physiochemical properties, such as density, viscosity, cloud point, pour point, flash point, and fire points, as well as engine performance parameters, including torque, power, fuel consumption, BTE, and EGT. CB20A50C50 and CB20A40C40 both had an average brake power that was higher than diesel fuel by 6.14 % and 1.25 percent, respectively. The average brake-specific fuel consumption decreased by 3.21 % to 8.29 % when using hybrid and single nano-additive blended fuels compared to CB20. CB20A50C50 exhibited a 20.38 % higher brake thermal efficiency than CB20. Notably, CB20C100 showed a 29.52 % reduction in HC and a 38.32 % reduction in CO, while CB20A50C50 demonstrated a 10.24 % decrease in NOx compared to CB20. Overall, the results of this study indicate that the generated fuel blends combining castor biodiesel and aluminum oxide/cerium oxide nanoparticles hold promise as alternate fuels for diesel engines, with positive impacts on engine performance and emissions.

Localized Perturbation Load Approach for Buckling Design of Thin-Walled Steel Cylindrical Shells under Partial Axial Compression

A thin-walled steel cylindrical shell is a common engineering structure that has an efficient load-carrying capacity. This structure is more easily subjected to partial axial compression loads in application, and buckling is the main failure mode. However, there are few available design methods for partial axially compressed steel cylindrical shells. Motivated by this, a design method called the localized perturbation load approach (LPLA) is proposed in this paper. The finite element framework for the application of LPLA is established. The location and number of perturbation loads are determined by considering the imperfection sensitivity and the buckling failure mode of partial axial compressed cylinders. A series of buckling experiments are carried out to validate the LPLA method. In addition, the reliability of LPLA for the design of cylindrical shells with different imperfection locations and dimensions is also verified. The results show that LPLA can give conservative and reliable lower-bound buckling loads. Therefore, LPLA can be used as a design method for thin-walled steel cylindrical shell structures under partial axial compression in actual engineering.

Characterization approaches affect asymmetric load predictions of hexagonal close-packed alloy

The anisotropic plasticity constants of the CPB06 criterion for Ti64, previously identified with experiments performed in all three dimensions, are applied here to evaluate the effect of the direct and inverse calibration strategies of the tensile-compression asymmetry parameter k on the predictive behavior of large deformations of the hexagonal close-packed (hcp) alloy. The direct calibration strategy is based on model fitting with experimental strain hardening data up to the onset of plastic instability. The inverse calibration strategy reduces prediction errors of the load-displacement curves of both the cylindrical bar tensile and the elliptical cylinder compression tests. The results provide interesting insights into the identification of the laws modeling large deformations of hcp materials.

Influence of the shutdown process of the driveline on the generator bearing life in the diesel generator set

Diesel generator sets are commonly used as power sources in transportation due to their versatility and cost-effectiveness. During the shutdown process, the diesel engine’s cylinder compression pressure would cause forced vibration in the driveline system through the crank linkage mechanism, resulting in unsteady loads that pose a threat to the bearing life. To address this issue, a coupling forward design method is proposed that takes into account the impact of unsteady loads on bearing life. An experiment was conducted on a 16V280 diesel generator set shutdown process, and a driveline dynamic model was established. The cumulative damage value that connects unsteady loads and bearing life was introduced to quantify the effect of unsteady loads on the bearing life during the shutdown process. The unsteady loads included torque fluctuation and collision forces. The results showed that reducing the driveline key gap and increasing the coupling stiffness can decrease the combined load on bearings and improve bearing life. A large stiffness coupling was designed to achieve shutdown smoothness and a 43.19% reduction in bearing life damage, confirming the design method’s feasibility concerning bearing life.

Investigation of the water resistance of non-sintered wrap-shell lightweight aggregates with high content solid waste and its application in water permeable bricks

Non-sintered solid waste lightweight aggregates can be used as building materials. However, its active hydration performance has brought challenges to its application. In this study, non-sintered waterproof solid waste wrap-shell lightweight aggregates (W-SWSLAs) were prepared from dredged sediments, steel slag, and other solid waste materials, and activator and waterproof agent were also added. The shell phase of W-SWSLAs was treated with inorganic aluminum salt waterproof agent (IWA) and silicone waterproof agent (SWA), respectively, to investigate the effects of different kinds and dosages of waterproof agents on the properties of the bearing capacity of single grain and water resistance. The performance of W-SWSLAs was assessed from the environmental, physicochemical and mechanical perspectives, respectively. In addition, its application in water permeable bricks was also studied. The results showed that when the addition amount of SWA was 0.08%, it could reach a good balance between the water resistance and mechanical performance of W-SWSLAs. The leaching values of pollutants were well below the limit value set out in the legislation. The water absorption rate, cylinder compression strength and softening coefficient of W-SWSLAs were 8.73%, 20.35 MPa, and 0.84, respectively. The permeability coefficient of water permeable bricks prepared from W-SWSLAs (W-SWSLAPB) was 0.022 cm/s, and the strength loss rate was 10.4% after 25 freeze–thaw cycles, which all met the current Chinese National Standards. The production of W-SWSLAs, whose solid waste content is 95.17 wt%, provides an eco-friendlier approach to converting hazardous and industrial solid waste into high value-added materials.

Experimental study of RCCI engine – Ammonia combustion with diesel pilot injection

Ammonia is seen as one potential carbon-free fuel, especially for maritime applications. Since SI engines require a significant ignition energy for large cylinders, engine manufacturers are targeting the use of ammonia in Compressed Ignition (CI) engines. Because of ammonia’s high auto-ignition temperature, to ensure that the combustion occurs in a CI engine, a pilot injection of a higher reactivity fuel must be used, as in Reactivity Controlled Compression Ignition engines. In the present study, the objective was to provide first unique data about the efficiency and pollutant emissions for a single cylinder compression ignition engine with a diesel energy fraction as minimum as possible (down to less than 2%) at a constant 1000 rpm. Experiments cover the impact of a wide variation of equivalence ratios of NH3-air mixtures from ultra-lean to slightly rich conditions. CO2, CO, NH3, NOX, N2O, UHC values were measured with a Fourier Transform Infrared (FTIR) spectrometer. Results of CO2 and N2O are presented as CO2-Equivalent (CO2eq) impact. Combustion stability was achieved for most conditions but not for the leanest ones. Furthermore, under lean conditions for a similar ammonia content, the minimum CO2eq is reached with a slightly higher Diesel Energy Fraction than the minimum possible. Finally, both leanest and richest conditions present a higher level of CO2eq compared to the range of ammonia/air mixtures at stoichiometry or just below.

Efficacies of suggested strength-based prediction models for estimation of compressive and tensile properties of normal concrete

One of the most crucial challenges faced by today’s construction industry for a speedy delivery is undeniably the ‘time-factor’ accompanied by promised quality within the framework of distinct budget. Strength based - Prediction models helps in estimating the early strengths as well as later-stage strength or strength at any age of concrete. Such models assist the structural and execution engineers in arriving at a fair judgement of compressive strength of concrete. A normal practice usually followed by the material testing laboratories and quality assurance cell at site is to assess the cube compressive strength of concrete which is an intrinsic engineering property governing the design and performance phase of structures. It is found from the literature that most of the prediction models that are formulated to estimate the compressive strength of concrete at any age are actually based on cylinder compressive strength of concrete. Therefore, this paper attempts to use some of the suggested prediction models with two sets of data, that is, one by considering experimental results of cube compressive strength found at the age of 7, 14 and 28-days and two by utilizing a conversion value, suitable cylinder compressive strength is obtained. These datasets are thoroughly used in the prediction models to accurately estimate the compressive strength of concrete. Similarly, appropriate prediction models are sought to determine the split tensile strength of normal concretes based on cubic compressive strength and cylinder compressive strength. Particularly, results of the present study showcase that although the prediction models are developed based on cylinder compressive strength, they can agreeably be used on cube strength data as the ratio of (Pi/Ai) obtained is the higher range of 0.85-1.00 and with only an early cube strength result, it is possible to predict an accurate value of split tensile strength of concrete at an age of 28-days. The effectiveness of suggested prediction models through statistical parameters are determined and their efficiencies are found to be in the higher range of 94% to 98%.

Digital Image Correlation with a Prism Camera and Its Application in Complex Deformation Measurement.

Given the low accuracy of the traditional digital image correlation (DIC) method in complex deformation measurement, a color DIC method is proposed using a prism camera. Compared to the Bayer camera, the Prism camera can capture color images with three channels of real information. In this paper, a prism camera is used to collect color images. Relying on the rich information of three channels, the classic gray image matching algorithm is improved based on the color speckle image. Considering the change of light intensity of three channels before and after deformation, the matching algorithm merging subsets on three channels of a color image is deduced, including integer-pixel matching, sub-pixel matching, and initial value estimation of light intensity. The advantage of this method in measuring nonlinear deformation is verified by numerical simulation. Finally, it is applied to the cylinder compression experiment. This method can also be combined with stereo vision to measure complex shapes by projecting color speckle patterns.

Performance-emission optimization in a single cylinder CI-engine with diesel hydrogen dual fuel: A spherical fuzzy MARCOS MCGDM based Type-3 fuzzy logic approach

This paper presents a novel approach to optimize the performance and emission characteristics of a single cylinder compression ignition engine using diesel-hydrogen dual fuel. A TMI (timed manifold injection) system was designed employing an ECU (electronic control unit) for hydrogen induction into the engine manifold. The results showed a significant enhancement in BTHE (12.44% Max. enhancement at 85% full load condition under DH4 strategy) compared to base-diesel operation. The NOx emissions were enhanced to a maximum of 10.33 g/kw-hr at full load under the DH4 strategy. The emissions of UHC were found to be higher at lower loads and get significantly reduced to a maximum of 3.98 g/kw-hr at full load under the DH2 strategy. In comparison, soot emissions decrease substantially and are reduced to a maximum of 0.02 g/kw-hr at 85% full load condition under the DH5 strategy. The proposed method utilizes a Spherical Fuzzy MARCOS MCGDM-based Type-3 Fuzzy Logic approach, which integrates several criteria and uncertain inputs to improve decision-making. The paper outlines the theoretical framework of the approach and the experimental setup used for validation. The results demonstrate that the proposed method significantly reduces emissions while simultaneously improving the engine's performance. Overall, this study offers an innovative and effective solution for optimizing the performance and emissions of diesel-hydrogen dual fuel engines.

Practical approach for determining material parameters when predicting grain size after static recrystallization

The static recrystallization (SRX) behavior of 42CrMo steel was investigated by a non-isothermal hot compression test. The conventional empirical equation for SRX was applied to a finite element (FE) simulator using a nonconventional manner of parameter characterization. Parameter characterization was conducted by applying the FE-coupled optimization method to cylinder compression, which is an axisymmetric upsetting process. An accurate and practical flow stress model was used to precisely determine the critical strain value and define the instant when SRX occurred. The results revealed that the microstructural evolution during SRX was substantially influenced by temperature, strain rate, degree of deformation, and initial austenite grain size. The predicted recrystallized SRX grain sizes exhibited good agreement with the measured values when the model's parameters for the calculation of grain size were obtained using a FE-coupled optimization scheme.

Evaluation of the macroscopic formability of metallic materials using a cylinder compression test

Several flow features revealed by hot cylinder compression tests are macroscopically analyzed and compared. Materials including AISI 1025 (100–500 °C), AISI 52100 (900–1200 °C), AA6082 (20–300 °C and 350–550 °C), Ti–6Al–4V (500–800 °C) and AZ61A (250–400 °C) were grouped in terms of formability. The shapes of cylinder-compressed specimens were analyzed and related to formability. The addition of the maximum radius increase near the mid-plane and the averaged minimum radius increase at the two specimen-tool interfaces, i.e., the “cylinder compression evaluation factor” (CCEF), serves as an index of formability. To quantify the effect of temperature on formability, several metrics were used, including the CCEF and temperature softening formability index (TSFI). It has been shown that the CCEF and TSFI have utility for evaluating the formability of tested materials and that temperature softening greatly affects the formability of metallic materials.

Performance And Emission Test on A Single Cylinder Compression Ignition Engine Using Neem Oil Blends by Sonication

The transportation segment is the single biggest customer of oil determined vitality. Generally, fluid hydrocarbons have developed as the essential transportation fuel in light of their high vitality content per unit volume and as a result of the effortlessness of fluid fuel dealing with and conveyance frameworks rather than those required for strong or vaporous energizes. Thus, our present day transportation control plants have been intended to utilize fluid powers and oil refiners have, through a transformative procedure, been fitting to meet the prerequisites of cylinder motors. This fitting of the fuel to meet motor necessities must be reevaluated. As a transitional procedure, other vitality sources must be looked for which can be utilized as a part of altered cylinder motors. This transitional procedure could most recent a very long while as new but unclear, transportation frameworks are produced.

Performance and emission characteristics of salviniaceae filiculoides aquatic fern oil and SiO2 nano additive biodiesel in CI engine

This present study deals the engine performance and emission of adding SiO2 nano additives in novel salviniaceae filiculoides aquatic fern biomass derived biodiesel. The primary aim of this present study was to investigate the effect of adding SiO2 nano additives into the Azolla Oil Methyl Ester (AZOME) as a sustainable biodiesel in the Compression Ignition (CI) engine and studying the engine performance and emission effects. The Azolla Oil Methyl Ester was prepared via transesterification process and blended with as-present diesel with various percentages. The SiO2 nano particles are mixed with AZOME using sonication. The test was conducted using a single cylinder Compression Ignition engine with different blends of AZOME biodiesel. The fuel was injected into the engine at different spill timings as 20°, 23°, and 26° Crank Angle (CA) before (b) Top Dead Centre (TDC). According to the results the break thermal efficiency of AZOME and its SiO2 blends were improved with spill timings. On compare with the conventional diesel the Injection Time (IT) of 23° b TDC and the average Brake Thermal Efficiency (BTE) of AZ20 fuel at the retarded spill timing of 20° was raised by 3.38%, while the AZ100 fuel at 20° b TDC is decreased by 0.9%. However the emission of AZ100 fuel found to be lesser due to the presence of SiO2 nano additives. Thus the addition of SiO2 nano additives along with aquatic biomass Azolla Oil Methyl Ester reduced the emission without affecting the engine performance.

Automation of Temperature Measurement in Induction Motors of Hermetic Compressors Based on the Method of Temperature Rise by Resistance

Recent studies have proposed the use of artificial neural networks to establish a correlation between the cooling capacity of refrigeration compressors and the results of quick production quality tests. However, the temperature measurement method used in the tests reflects a high uncertainty in the estimated performance parameters, primarily because the measurement is performed on the compressor shell, which has large thermal inertia and does not accurately reflect the temperature changes observed during the tests. This study proposes a set of modules that allow the application of the method of temperature rise by resistance to estimate the winding temperature of the single-phase induction motor of the compressor in quick quality tests. The winding temperature is a better estimate of the temperature at which the refrigerant fluid enters the compression cylinder and its use solves many of the problems associated with the traditional method. Validation tests show that the proposed solution is capable of automating the measurement in a safe, agile, and metrologically more reliable manner than the method currently used in quick quality tests in the industry.

CONCRETE MIX DESIGN USING ABRAMS AND BOLOMEY METHODS

This research studied concrete design methods. To design concrete using two methods, including the Abrams law and the modified Bolomey method. Concrete with assumed compressive strength 25, 30, 35, 40, and 45 MPa was researched. The research was conducted in the laboratory using two types of samples: cubic 15x15x15cm for compressive strength tests and cylinders ϕ-15cm, h-30cm for the splitting strength tests using the Brazilian method. The analysis of the cement content in the composition of 1m3 of the mixture showed very large differences depending on the calculation method used. The cement content calculated according to the Abrams method ranged from 180 kg/m3 (25MPa) to 497 kg/m3 (45MPa) depending on the class and determined according to the Bolomey method from 286 kg/m3 (25MPa) to 983 kg/m3 (45MPa). Significant differences were shown in the concrete strength test. The obtained test results can be the basis for future modifications of the concrete design methods, taking into account additives and admixtures, and can be the basis for the application of artificial neural networks (ANN) to design the composition of concrete.

Experimental Investigations and Numerical Modelling of Compression Ignition Engine Fuelled With Diesel and Biodiesel Blend

In this study, diesel fuel and two hundredth by volume of synthesised biodiesel from waste coconut oil (WB20) were used as fuel in unmodified, naturally aspirated, single cylinder compression ignition engine to study their performance and combustion characteristics at full load condition. Numerical studies were carried out with the use of CFD and compiled with the experimental results. FORTE software was used for CFD simulation. Methyl-palmitate (MPA) and Dodecane (C12H26) were used as surrogate fuels for biodiesel and diesel fuel respectively. The variation of special parts for diesel fuel and WB20 with CI engine in-cylinder pressure, in- cylinder temperature and mass fraction of O2, CO and NO emission at 10p and 20p ATDC were analysed. The mass fraction contours of in-cylinder temperature, O2, CO and NO for diesel fuel and WB20 were found to be decreased with increase in crank angle from 10o to 20° ATDC. The maximum BTE, in-cylinder pressure, in-cylinder temperature, O2, CO2 and NO were obtained for WB20 at 10° ATDC.

Accurate Flow Characterization of A6082 for Precision Simulation of a Hot Metal Forming Process

The flow behaviors of metallic materials are sensitive to state variables, including strain, strain rate, and temperature. In particular, the temperature effect on the flow behavior is of great importance. The flow information is usually obtained at the sample strain rates and temperatures from the hot cylinder compression test. However, this test is inevitably exposed to undesirable effects of friction and temperature on flow characterization. This study reveals their impact on the flow curve of an A6082 alloy. The unique features of its flow behavior and the inaccuracy of as-received, primitive flow information are emphasized. Using a systematic way of correcting the friction and temperature effects, the flow curves with high accuracy in terms of the compression load-stroke curve obtained from the test are calculated. It was revealed that the both the friction and temperature compensation of the primitive flow curves bring a minor change in the flow curves of the A6082 alloy, which is quite different from other commercial light metals. This phenomenon caused by the unique features of the flow behavior of the A6082 or other aluminum alloys will be critical to solving various process and quality matters confronted by the engineers in the hot metal forming industry.

Solitary waves and chaos in nearly compressible thermo-hyperelastic cylinder

Solitary waves and chaos in nearly compressible thermo-hyperelastic cylinder