Ramp Loading Research Articles

Pengendalian Mutu Crude Palm Oil (CPO) Dengan Metode Control Chart dan Failure Mode and Effect Analysis (FMEA) Pada Pabrik Kelapa Sawit PT.XYZ

The purpose of this research is to analyze the consistency of daily CPO quality at the palm factory PT. XYZ for the last 3 months, that is January, February and March 2021. Based on three quality parameters, that is free fatty acids (FFA), water content and dirt content. The data is evaluated by the I-MR chart method and then compared with the quality specifications of the company and the buyer. Meanwhile, critical points and critical conditions that most influence the quality of palm oil were identified using the FMEA method. The results showed that FFA and water content of CPO were still not statistically controlled, which was indicated by the presence of data points that were outside the control limits. The parameter of FFA CPO quality in January 2021 is the highest with an average of 3.91%. The highest water content quality parameter is in March 2021 with an average 0.398%. And the highest dirt quality parameter was in February 2021 with an average 0.039%. The cause of the variation in the quality CPO was identified from 5 critical conditions where the highest RPN value is the use of restant fresh fruit bunch in the palm oil processing process. The proposed improvement that can be given to palm factory PT.XYZ is to implement a fast processing system using the FIFO (First In First Out) system so that the raw materials that is fresh fruit bunch are not too long and pile up at the loading ramp.

Study on the Testing Method of Relaxation Modulus under Spherical Indenter Loading

Viscoelastic materials are widely used in various fields. In order to better use viscoelastic materials in various working conditions, it is necessary to master the material properties of viscoelastic materials. Relaxation modulus is a characterization method of viscoelastic material properties. In this paper, by analyzing that viscoelastic materials are time-domain related parameters, the load-time curves are obtained by using the spherical indentation instrument to carry out the ramp loading indentation test at different speeds. According to the law of ramp strain history loading, the data at different velocities are summarized and a method for judging the linear viscoelastic boundary of viscoelastic materials in spherical indentation tests is obtained. Aggregate the load-time data at different speeds to obtain a set of valid data for a longer period of time. A method of measuring the relaxation modulus using the ramp-constant strain history is proposed. Compared with the ramp loading test method, it is simple and easy to operate, and it can make up for the short time period of the measured data in the ramp loading test. The experiment verifies the feasibility of the method of ramp-constant strain history.

One-dimensional consolidation of unsaturated–saturated soil system considering pervious or impervious drainage condition induced by time-dependent loading

Since the ground with unsaturated soil layer and saturated soil layer is very common in most areas, a more comprehensive analytical solution is essential for the accurate prediction of ground consolidation behavior. In this paper, the one-dimensional consolidation theories for unsaturated and saturated soils are introduced to simulate the consolidation characteristics of the different soil layers, and the hypothetical soil interface of two layers that only allows pore water to flow is supposed in this model. After using the decoupling and Laplace transformation techniques to the coupled governing equations, the general Laplace-domain solutions are proposed under the permeable or impermeable surface for ground consolidation that an unsaturated–saturated ground with finite thickness subject to arbitrary time-dependent loading. The results in the temporal domain for the excess pore pressures and soil settlement are numerically obtained by Crump’s algorithm. The methodology and proposed solution are validated by some published solutions in the literature. Based on the proposed solutions under the three representative boundary conditions, the temporal behavior of ground subjected to ramp loading is explored. The results show that boundary condition would significantly affect the evolutions of excess pore pressures and further change the ground settlement.

Effect of engine failure on aerodynamic characteristics of a light transport aircraft model

In-flight engine failure has always been a hazardous situation in case of a single-engine aircraft associated with losing altitude and making a landing within the available gliding range. In the event of a multi-engine aircraft, this situation improves markedly due to the potential flight continuation. The necessary conditions to continue a flight are available excess thrust, satisfactory aerodynamic performance, and a fixed-wing control. If the half of engine thrust is lost, which adversely affects a rate of climb, the most critical flight modes are the take-off and go-around procedures performed at low altitudes using the engine asymmetric thrust. Ensuring flight safety in these modes requires extensive experimental studies in wind tunnels to simulate the basic flight envelope with an inoperative engine. The aim of studies is the effect of a critical engine failure on the aerodynamiccharacteristics of an aircraft model as well as ensuring the required efficiency of the flight controls to dampen the yaw and roll moments that arise during an asymmetric thrust flight. The complexity of solving the problem is determined by the necessity of recovering from the substantial yaw, roll moments and by a significant decrease in the wing lifting efficiency along with an increase in a drag force which limits a climb rate and aircraft control. This article presents an analysis of the effect of critical engine failure on the aerodynamic characteristics of a light twin-engine transport aircraft model in the wing take-off and landing configurations. The aircraft aerodynamic configuration is made according to the classic pattern with the high-mounted tapered wing and deck-type empennage. The high lift devices comprise a double-slot hinged flap with a fixed deflector. The aircraft is equipped with a loading ramp with a relatively short flat rotatable part of the lower fuselage surface. Experimental studies of the longitudinal and lateral characteristics of the model with installed simulators of a power plant were carried out in TsAGI low-speed wind tunnel T-102. The analysis of engine failure effect on the model aerodynamics was executed in changing the load factor within the range B = 0.3…2. The capabilities to dampen the yaw and roll moments, using the primary flight controls (rudder and ailerons), were determined.

A Microscopical Model for Incubation Time and Its Associated Dynamic Load-Carrying Capacity

In recent decades, the incubation time has become a critical parameter to study dynamic failures for materials, but its underlying physical meaning is still vague and the corresponding model remains lacking. In this study, we first established a theoretical framework to evaluate incubation time, wherein a double atomic chain model with atomic thermal vibrations is leveraged. We leveraged three external force loading conditions to analyze incubation time and its associated dynamic load-carrying capacity (DLC). It can be found that the theoretical results for three metal materials (iron, tungsten and aluminum) exhibit reasonable consistencies with the experimental data, thus the model can be used to conduct preliminary studies for incubation time and DLC. The model suggests that, under the ramp loading with a platform amplitude of static strength, the amplitude duration does not remain constant but can quickly reach a constant with increasing ramp or loading rate, which implies that treating incubation time as a constant parameter is reasonable and thus lays a solid foundation for the previous macroscopic models on basis of incubation time. Meanwhile, it also suggests that the rate enhancement effect of failure strength can be obtained from external load and the constant atomic bond parameters without involving microscopic changes in material properties. Therefore, we microscopically unravel the rate enhancement effect of failure strength. Our study indicates that this effect is indeed a structural response, which accords with the previous macroscopical model.

DESKRIPSI INDUSTRI PENGOLAHAN KELAPA SAWIT DI PT. TRI BAKTI SARIMAS PKS 2 IBUL, RIAU TAHUN 2020

Palm oil processing is one of the determining factors for the success of an oil palm plantation business. This study is aimed to examine the palm oil processing industry at PT. Tri Bakti Sarimas PKS 2 Ibul, Riau in 2020 where the subject of study is devoted to the palm oil processing system into CPO (Crude Palm Oil) and PKO (Palm Kernel Oil). The descriptive method is used in this study and data are taken through experiments, observation, interviews and documentation. The results showed that the processing of palm oil into CPO and PKO is processed to several stages and processes, namely weighing, grading and sorting, loading ramp, splitter, sterilizer, thresher, digester and press. PT. Tri Bakti Sarimas has carried out the processing of palm oil in accordance with standard operating procedure.

Effect of Ti/Si and Ti/TiN/Si interlayers on the structure, properties, and tribological behavior of an a-C film deposited onto a C17200 copper-beryllium alloy

Reduced hardness and wear resistance may limit SAE C17200 copper‐beryllium alloy use in manufacturing applications, such as plunger tips of die casting machines and as cores and inserts for steel dies in injection molding processes. In order to improve the surface properties of Cu—Be alloys, amorphous carbon (a-C) films have been selected since these coatings may show high hardness, low wear rate and low coefficient of friction. However, the adhesion of carbonaceous films on Cu—Be alloys remains a challenge. Two interlayer compositions (Ti/Si and Ti/TiN/Si) were deposited onto Cu—Be disks and silicon wafers to assess amorphous carbon adhesion on substrates made of Cu—Be alloy. The microstructure and topography of the coatings were examined by Field Emission Scanning Electron Microscopy (FESEM) coupled with X-ray dispersive energy spectroscopy (EDS). The chemical composition depth profile was measured by glow discharge optical emission spectroscopy (GDOES), which confirmed distinct coating layers of Ti, Si, a-C (C1 and C2 conditions-pDCMS). A TiN extra layer presence was obtained for the C3 and C4 conditions-pDCMS reactive, confirmed by small angle XRD analysis. Raman scattering spectroscopy showed a higher quantity of sp3 carbon bonds for C3 and C4 coating conditions compared to C1 and C2. Instrumented indentation tests indicated a higher hardness and reduced elastic modulus for C3 and C4 coating systems, corroborating Raman results, in terms of a higher concentration of sp3 bonds. Scanning electron microscopy (SEM), atomic force microscopy (AFM), and coherence correlation interferometry (CCI) were used to characterize the coatings' surface features and scratch tracks after the tests. In addition, ramp load scratch tests were conducted to assess coating adhesion to the Cu—Be alloy substrate by measuring critical loads and the coefficient of friction. The highest critical loads to failure (Lc2) and (Lc3) were found for the Ti/TiN/Si interlayer sample (C4 condition), indicating that this interlayer improved the coating contribution to a gradual increase in the hardness and promotion of an enhanced adhesion strength of the a-C coating.

ANALYSIS OF CRUDE PALM OIL (CPO) QUALITY BASED ON VACUUM DRYER PERFORMANCE AT PRIMAJASA PALM OIL MILL

The products produced at the Primajasa Palm Oil Mill are Crude Palm Oil (CPO) and palm kernel (kernel). The palm oil processing process goes through several stations, including loading ramp station, sterilizing station, threshing stations, digesting and pressing station, clarification station, and kernel stations. In the palm oil processing industry, the main factors that can cause damage palm oil quality are high moisture content and free fatty acid (FFA) levels. This study aims to analyze the quality of CPO based on the performance of the vacuum dryer at the Primajasa Palm Oil Mill as seen from the free fatty acid (FFA) and moisture content. The average results obtained from the analysis of the moisture content of CPO before entering the vacuum dryer and after leaving the vacuum dryer were 0.57% and 0.27%. Meanwhile, the average results obtained from the analysis of FFA CPO levels before entering the vacuum dryer and after leaving the vacuum dryer were 3.63% and 3.57%. Based on these results, it is known that a vacuum dryer can reduce the value of moisture content and FFA levels contained in CPO. These results also indicate that the moisture content and free fatty acid (FFA) content in the sample are in accordance with the national quality standard of CPO.

Exploration of an Inflection Point of Ventilation Parameters with Anaerobic Threshold Using Strucchange.

(1) Background: When measuring anaerobic work threshold (AT), the conventional V-slope method includes the subjectivity of the examiner, which cannot be eliminated completely. Therefore, we implemented an engineering method using strucchange to objectively search for the inflection point of AT. (2) Methods: Seventeen subjects (15 men and 2 women) were included in the study. The subjects rode an ergometer and performed a ramp load test for 18 min and 30 s. (3) Results: In VE (Ventilation), 11 out of 12 subjects had the same results with 95% confidence intervals for the AT by the strucchange and respiratory metabolic apparatus. In VCO2 (Carbon dioxide emissions), 9 out of 12 subjects had the same results with 95% confidence intervals for the AT with the strucchange and respiratory metabolic apparatus. In VE, 3 out of 12 subjects showed the same results for respiratory metabolic analysis and the AT by the V-slope method. In VCO2, 3 out of 12 subjects showed the same results for the respiratory metabolic analysis and AT by the V-slope method in VCO2. (4) Conclusions: Strucchange was more objective and significant in identifying the AT than the V-slope method.

Finite difference method with laplace transform technique for vertical drains

The paper present finite diference method (FDM) with Laplace transform technique for vertical drains. This method is capable of simulation of multi loading with time and complex boundary conditions. The Laplace transform technique is also ultilized in order to simplify the derivative function of time to an algebra function. The discreted function then can easily determine the pore pressure at each points. The pore pressure and average consolidation degree by the present solution shows good agreement with previous solutions in three differences load applying: instant loading, single ramp loading and multi-ramp loading. This paper also proposes a discreted 10 points is a practical application for multi-ramp loading with the error in predicting average consolidation degree less than 5%. In order to verify the efficient of the present solution, a real embankment treated by vertical drains with vacuum consolidation technique are analyzed. The pore pressures and settlements have been compared with field data and previous researchs.

Investigation of AlN ceramic anisotropic deformation behavior during scratching

To explore the anisotropic deformation behavior of aluminum nitride ceramic during processing, ramp and constant load scratch experiments were conducted with Vickers indenter. Characteristics of deformation anisotropy were observed in ramp-load scratch with differences found in the directions of pile-ups, slip lines and cracks produced by grains with various orientations. Constant-load scratches were conducted to explore the anisotropic deformation behavior in plastic stage. Obvious differences were found in scratch pile-up height and residual depth of grains with different orientations. As the grain orientation Euler angle changes from the basal to the two prism surfaces, the residual depth of the scratch gradually increases. Molecular dynamics simulation was performed to disclose the mechanisms of anisotropic dislocation and deformation during scratching. The activation of the slip system for different grain orientations was calculated by a scratch Schmid factor model which was verified by the observation of pile-ups and slip lines around the scratches.

Equation of state and strength of diamond in high-pressure ramp loading

Diamond is used extensively as a component in high-energy-density experiments, but existing equation of state (EOS) models do not capture its observed response to dynamic loading. In particular, in contrast with first-principles theoretical models of equilibrium multiphase EOS, no solid-solid phase changes have been detected, and no general-purpose EOS models match the measured ambient isotherm. We have performed density functional theory (DFT) calculations of the diamond phase to $\ensuremath{\sim}10$ TPa, well beyond its predicted range of thermodynamic stability, and used these results as the basis of a Mie-Gr\"uneisen EOS. We also performed DFT calculations of the elastic moduli, and calibrated an algebraic elasticity model for use in simulations. We then estimated the flow stress of diamond by comparison with the stress-density relation measured experimentally in ramp-loading experiments. The resulting constitutive model allows us to place a constraint on the Taylor-Quinney factor (the fraction of plastic work converted to heat) from the observation that diamond does not melt on ramp compression.

Influence of substrate type and film thickness on the failures of Zr-based thin-film metallic glass under nanoscratch

Nanoscratch experiments under constant and ramp loading conditions are performed to investigate the delamination, and spallation characteristics of Zr-based thin-film metallic glass (Zr-based TFMG, Zr65Cu15Al10Ni10). TFMGs with different film thickness = 200, 500, 1000 nm are deposited over hard and soft substrates via DC magnetron sputtering process. Coefficient of friction (COF) is measured to be less about 0.03 regardless of scratch mode and maximum normal load. The critical load for thin film delamination and spallation reveals that the deformation and failure mechanism of Zr-based TFMG significantly change with film thickness and substrate type. The failure mechanism is characterized by observing the scratch grooves via optical and scanning electron microscopes (SEM). The adhesion energy between thin film and soft substrate is calculated based on Burnett and Rickerby model, and an increase in adhesion energy with interfacial layer thickness is reported.

Volar versus combined dorsal and volar plate fixation of complex intraarticular distal radius fractures with small dorsoulnar fragment \u2013 a biomechanical study

Complex intraarticular distal radius fractures (DRFs), commonly managed with volar locking plates, are challenging. Combined volar and dorsal plating is frequently applied for treatment, however, biomechanical investigations are scant. The aim of this biomechanical study was to investigate volar plating versus double plating in DRFs with different degrees of lunate facet comminution.Thirty artificial radii with simulated AO/OTA 23-C2.1 and C3.1 DRFs, including dorsal defect and lunate facet comminution, were assigned to 3 groups: Group 1 with two equally-sized lunate facet fragments; Group 2 with small dorsal and large volar fragment; Group 3 with three equally-sized fragments. The specimens underwent volar and double locked plating and non-destructive ramped loading in 0° neutral position, 40° flexion and 40° extension.In each tested position, stiffness: (1) did not significantly differ among groups with same fixation method (p ≥ 0.15); (2) increased significantly after supplemental dorsal plating in Group 2 and Group 3 (p ≤ 0.02).Interfragmentary displacements between styloid process and lunate facet in neutral position were below 0.5 mm, being not significantly different among groups and plating techniques (p ≥ 0.63).Following volar plating, angular displacement of the lunate facet to radius shaft was significantly lower in Group 1 versus both Group 2 and Group 3 (p < 0.01). It decreased significantly after supplemental dorsal plating in Group 2 and Group 3 (p < 0.01), but not in Group 1 (p ≥ 0.13), and did not differ significantly among the three groups after double plating (p ≥ 0.74).Comminution of the lunate facet within its dorsal third significantly affected the biomechanical outcomes related to complex intraarticular DRFs treated with volar and double locked plates.Double plating demonstrates superior stability versus volar plating only for lunate facet comminution within its dorsal third. In contrast, volar plating could achieve stability comparable with double plating when the dorsal third of the lunate facet is not separated by the fracture pattern. Both fixation methods indicated achievable absolute stability between the articular fragments.

Low-cycle fatigue life and duration-of-load effect for hybrid CLT fabricated from lumber and OSB

Given the nature of cross-laminated timber (CLT), with an orthogonal arrangement and rolling shear characteristics of transverse layers, it has a more complex duration-of-load (DOL) effect than other engineered wood products, such as glued-laminated timber. Developing hybrid CLT (HCLT) with structural composite lumber, which can improve the mechanical properties and material sources of CLT, is gaining increasing interest. Construction oriented strand board (COSB) and spruce-pine-fir (SPF) dimension lumber were used to fabricate HCLT specimens for this study. The regular SPF CLT and HCLT specimens having different lay-ups and numbers of layers were subjected to low-cycle fatigue bending and shear loading tests. The Foschi and Yao damage accumulation model was calibrated using the test results. The DOL factors for the CLT and HCLT specimens were calculated using the stress ratio evaluation method. Results showed that the primary failure modes for the fatigue test specimens were the same as those observed in previous short-term ramp loading tests, and a good fit was observed between the model's predictions and the test data. The DOL factor corresponding to a load duration of 50 years, for a three-layer shear CLT specimen, was determined to be 0.53, which was lower than that recommended in CSA O86-19. The fatigue life and long-term performance of CLT were improved by using COSB panels as CLT layers. The HCLT specimens that used COSB only as the transverse layer showed advantages in fatigue life, long-term performance, and practical applications.

ANALISIS KEBUTUHAN ALAT ANGKUT TBS DI PT. BERAU KARETINDO LESTARI KECAMATAN SEGAH KABUPATEN BERAU PROVINSI KALIMANTAN TIMUR

This research is motivated by the processing of palm oil, transportation factors get special attention.The transportation of palm fruit from the garden to the factory should be as fast as possible so that thefruit harvested today can be processed directly so that free fatty acids are not high. Extensive oil palmplantations and garden conditions far from the factory, it will be more difficult to regulate the entry ofFresh Fruit Bunches (TBS) to the Palm Oil Factory (PKS), so that the company must have a goodmanagement system that can run effectively and efficiently so that it needs proper transportation forperushan so that it can transport all tbs harvested by minimizing time, cost and maintain the quality ofTBS.From the description above, the formula that can be formulated in this study is to know the time oftransportation, the needs of transport equipment and what obstacles are encountered at the time of TBStransportation. While the limitations of the problem there is tbs transport research contained in fadelingBrafo, Alfah and Delta with different distances (near, medium and farthest). The purpose of this researchis to know the process of planning the needs of TBS conveyances, as well as knowing the obstacleswhen transporting TBS.The results of research conducted at PT. Berau Karetindo Lestari shows that tbs transportationplanning includes the production of TBS per day, TBS transport time, availability of conveyance,transportation needs and constraints in transportation. In Bravo afdeling requires 2 units of tarktor, forafdeling Alfah 4 units taktor, and afdeling Delta requires 3 units of tractor. As for the needs of the truckon Loading ramp 1 as many as 10 units and Loading ramp 2 to 8 units. This is obtained after calculatingthe number of transport equipment needs to transport TBS every day. For the overall needs of thecompany, tractors are needed as many as 17 and DT as many as 18 units. As for the obstacles at thetime of tbs transportation, namely, the road conditions in TPH are not good and the distance of thefactory is so far that it takes so much time to get to the factory.

A comparative study: The effect of current loading modes on the cold start-up process of PEMFC stack

The start-up of the proton exchange membrane fuel cell (PEMFC) at temperatures below the freezing point is considered one of the major obstacles hindering the widespread commercialization applications of fuel cells. In this work, a one-dimensional transient numerical model is adopted to study the effects of five different current loading modes on the stack start-up from −20 °C. They are constant current loading mode, constant slope ramp loading mode, variable slope ramp loading mode, zigzag current loading mode, and stepwise-changed current loading mode. The detailed comparative analyses are presented for a better understanding of the cold start-up process. Three levels (good, appropriate, and inferior) are used to evaluate the performance of the current loading modes. The results show that the stepwise-changed current loading mode is the best among the five modes because it has the advantages of appropriate start-up time, temperature rising rate, ohmic resistance, heat generation rate, ice volume fraction, and water production rate.

Pressure control of fixed displacement variable speed radial piston pump using PID controller

In the present studies attentive to control the variable pressure of fixed displacement variable speed radial piston pump by controlling the angular speed of pump-motor system with a PID controller at ramp and wavy type load. The pressure-flow simulation of pump designed in MATLAB Simulink with an appropriate silencing groove valve plate of the pump. The proposed PID controller designed in Simulink framework to control the pump-motor speed to accomplished the demand pressures at ramp and wavy type load and the load accustomed by varying the needle valve orifice area. PID controller gain value optimised by minimising the tracking error of the pump pressure responses.

Structural phase transition and amorphization in hexagonal SiC subjected to dynamic loading

Understanding the dynamic behavior of silicon carbide (SiC) at extreme conditions is critical for applications such as coatings and armor. Revealing the plasticity and phase transition in SiC under intensive dynamic loading is among the key concerns. However, the effects of polytypes in SiC as well as the various loading conditions on its dynamic material responses are still not well understood. Here we carry out a series of large-scale molecular dynamics (MD) simulations to explore the inelastic responses of hexagonal SiC subjected to shock and ramp compression along the [0001] direction. The shock responses present three regimes sequentially as the shock particle velocity is increased from 0.5 km/s to 6 km/s: a single elastic wave, a multi-wave structure consisting of an elastic-plastic wave followed by two consecutive phase transition waves, and finally, an overdriven structural phase transformation wave. The original wurtzite structure is observed to transform into a 6-coordinated rock salt structure through a 5-coordinated intermediate structure. Furthermore, slip along the <112‾0> direction on the (0001) plane causes multiple stacking faults and amorphization when subjected to intense shock compression. The effects of temperature and strain rate on the material responses of hexagonal SiC are decoupled by performing ramp loading simulations. The results reveal that a lower temperature rise impedes atomic motion while a lower strain rate promotes it, highlighting a competitive effect. Besides, due to the limited availability of slip planes, dynamic compression can lead to the formation of nanograins in hexagonal SiC, and nanograins refinement with increasing shock intensity is observed. These results provide important insights into the deformation of SiC polytypes under extreme conditions and promote the understanding of the dynamic properties of hexagonal structure covalent materials.

Analytical Solutions for the Radial Consolidation of Unsaturated Foundation with Prefabricated Vertical Drain Based on Fourier Series Expansion Theory

This paper presents the analytical solution of the radial consolidation of a prefabricated vertical drain (PVD) foundation under the unsaturated condition. In the proposed modeling, air and water phases in the foundation are thought to dissipate horizontally toward to the drain, and the smear effect, drain resistance and external time-dependent loading are fully considered. The analytical mathematical tools, namely the general integration method, Fourier series expansion method, decoupling method and the constant variation method, are utilized to solve the partial differential equations. Moreover, the current solutions are verified with existing solutions in the literature. Finally, a case study considering the ramp loading and exponential loading is conducted to investigate the consolidation patterns under various loading parameters. The results show that smear effect and drain resistance can significantly hinder the dissipation process of excess pore pressures, and different external loading types will lead to various dissipation characteristics (i.e., peak values).