Compression - Science topic

Hello,

I had the same problem and it turned out that I was trying to run an SOC wannier calculations (spinors=True) on the non-spin DFT case. This rather misleading meassage appeared althtough "spinor_projections" block was inside the nnkp, but pw2wannier was looking for the "projections" block instead (non-spin case) probably because it uses the QE data for the check.

Regards,

Eleni

Implementing CNG over diesel offers long-term cost savings, reduced emissions, and alignment with sustainability goals. However, it requires significant initial investments in infrastructure and vehicles. CNG is ideal for short-haul fleets in regions with strong infrastructure, while diesel remains preferable for long-haul operations due to its established supply chain and higher energy density.

Young's modulus measures a material's stiffness under both tension and compression, assuming linear elasticity. Compressive modulus, however, specifically measures stiffness during compression, making it more relevant for hydrogels, which often experience compressive forces. While Young's modulus can be derived from both tensile and compressive tests, compressive modulus is often preferred for hydrogels due to their nonlinear behavior and the prevalence of compressive loading in their applications. The choice between the two depends on the specific hydrogel, its intended use, and the experimental setup. For example, consider a hydrogel used in tissue engineering. If the hydrogel is implanted and primarily experiences compressive forces from surrounding tissues, compressive modulus would be a more relevant measure of its mechanical properties. This modulus would provide information about the hydrogel's ability to withstand these compressive forces and its potential to support cell growth and tissue regeneration. On the other hand, if the hydrogel is used in a device that involves both tensile and compressive forces, Young's modulus could be a more appropriate measure, as it considers the material's response to both types of stress.

Use frigorific liquid in a capsulated system, the part expose to sun increase the pressure which can move to track the sun!

Success!

CYS remains virtually unchanged when small surface cracks appear in the material, whereas YS can decrease several times.

Use option "Nonlinear estimation" of the software StatSoft Statistica and explore the resids obtained for independety, stochasticity and normal distribution. I advice You to use quartic polynomial for SSD with the 4 parameters: Young modulus E0, conitional yield sytain t, this for yield stress Yt and the slope Et. You'll obtain the estimates and their Student-criteria and adj-R2 too. (See my papers on the RG)

Thank You very much, dear Ahmad! It is almost my case but stretching instead of compression. It is necessary only to change the sign of the stretching parameter on the opposite one.

Hi,

How do you get the stress-strain for the tension part experimentally? I am working on the mortar.

Dear Doctor

Go To

[Reinforced concrete (RC) shear walls are the major lateral load-carrying structural components in high-rise buildings. Under strong earthquake motions, the axial loads of RC walls are not constant axial compression, but may be in tension, resulting in the axial load of RC walls varying from compression to tension. In this study, three RC slender wall specimens (shear-to-span ratio λ = 2.0) were tested to study the effect of the fluctuating range and loading patterns of variable axial forces on their cyclic behavior, including failure modes, hysteretic response, strength and deformation capacity. Test results indicated that the final failure of RC slender walls subjected to variable axial forces was controlled by flexural failure in the compressive-flexural direction. The hysteretic curves of RC slender walls were asymmetric and substantively different from the hysteretic curves of RC slender walls with constant axial loads. The fluctuating range of axial forces had a limited influence on the shape of hysteretic curves, while the loading patterns significantly changed the shape of these hysteretic curves. Under the variable axial forces, the lateral strength and deformation capacity of RC slender walls depended on the fluctuating range of axial forces, while loading patterns had limited influence when the fluctuating range of axial forces kept constant. The loading patterns had a limited influence on the lateral stiffness of RC slender walls, while the increase of fluctuating range of axial forces increased the difference between compressive-flexural and tensile-flexural lateral stiffness. No matter in tensile-flexural or compressive-flexural directions, the assumption that the wall section remains plane after deformation is suitable for RC slender walls under the variable axial forces, and enables reasonable estimations of yielding and peak strength. Finally, a finite element model was developed for predicting the cyclic behavior of RC walls under the variable axial loads.]

Thanks Harold Berjamin ! The suggestions are helpful.

Let's take another example of seismic protection.

We take a scaffolding with its screws, place it under a reinforced concrete slab and raise its screws towards the slab. The screws, unable to rise any higher than the barrier of the slab, begin to compress the scaffolding frames.

The scaffolding becomes trapped between the ceiling and the floor.

1. this scaffolding is not overturned by a tipping moment 2. it is not displaced by a lateral force 3. It is not bent by a bending moment. 5. is not affected by shear forces or shear failures 6. does not exhibit tensile stresses

This is exactly what I do in buildings I place a ceiling coming from the ground.

Which scientist will say I am wrong? If this scaffolding just rested on the ground without the screws, would it have the same behavior?

More here. https://www.scirp.org/journal/paperinformation?paperid=130175

Dear,

I did the same work, I compared the numerical results with the analyical solution. It works perfectly with sigma_11 but not with sigma_12. Have you an idea for this problem.

We have all three in our labs, arranged for plastics application. When i had a choice i'd rather use a Zwick with automatic Makro extensometer but MTS or Instron could be sometimes also ok with their clip-ons elongation measurement (suitable only for hard plastics and not very convenient for E-modul).

Hi, you can check the reaction forces in each loading (tensile and compression), then, divide them to the area of section.

Martijn Jannink thank you for your advice:)

Dear Ajay Jayswal ,

When you are simulating quasi-static compression using ANSYS Workbench Explicit Dynamics, it's important to set up the simulation parameters properly to ensure accurate results such as:

If Automatic Mass Scaling is not working as expected, you may need to troubleshoot the issue or manually adjust the mass scaling settings. Additionally, consulting ANSYS documentation, forums, or seeking assistance from experienced users may help in resolving specific issues or optimizing simulation settings for your particular case.

I hope this helps you to achieve better results in your quasi-static compression analysis using ANSYS Workbench Explicit Dynamics. If you have any further questions, feel free to ask!

Thanks Namkyeong Cho

These are some possible points of discussion as I have gathered with help of AI

Hydrogen Embrittlement in Metal Cylinders

Generally, embrittlement becomes a concern after months to years of exposure in compressed gas storage, depending on the factors mentioned above.

Multi-layered coatings: These can be effective in mitigating hydrogen diffusion. They work by creating a barrier path that lengthens the diffusion time. However, no coating is perfect, and complete elimination of diffusion might not be achievable.

Surface and Knudsen Diffusion: Even with limited random diffusion, surface and Knudsen diffusion can still occur. While multi-layered coatings can help with surface diffusion, Knudsen diffusion is more challenging due to its dependence on pore size within the material. Selecting steels with minimal such pores can help to some extent.

Hydrogen Storage Methods

Organic Liquid Hydrogen Carriers (LOHC)

Temperature Variations and Enthalpy Changes: LOHC processes involve exothermic hydrogenation and endothermic dehydrogenation reactions. During transport, temperature control is necessary to manage these energy changes. While some insulation can help, maintaining consistent temperature over long distances can be challenging.

Energy Efficiency: The efficiency of LOHC systems depends on the specific carrier molecule and process conditions. There are energy losses associated with both hydrogenation and dehydrogenation. Researchers are continuously working on improving these processes to minimize energy losses and improve overall efficiency.

Long-Distance Transport: LOHC remains a promising option for long-distance transport (greater than 250 km). Both first and second law efficiencies are crucial considerations, and research is ongoing to optimize these aspects.

Overall: While challenges exist, LOHC offers significant advantages for long-distance hydrogen transport.

From the second law of thermodynamics in an reversible process one has:

TdS=dU+p dV

where S is the entropy, T is the absolute temperature (in K), p the pressure and V the volume. For an ideal gas p=R T/V where R is the ideal gas constant. For an ideal gas the internal energy is only a function of temperature hence dU =Cv dT, where Cv is the specific heat at constant temperature. Also for an ideal gas R=Cp-Cv where Cp is the specific heat at constant pressure. Hence the second law of thermodynamics combined with the first law becomes:

dS/Cv=(dT/T)+ (R/Cv)(dV/V)

For an isothermal process dT=0 so that a compression dV/V<0 implies a reduction of entropy. For a gas with constant Cv one can furthermore write:

(S-So)/Cv=ln(T/To)+(R/Cv)ln(V/Vo)

and

R/Cv=gamma-1

Dear Maryame el-yazidi, the question is a bit confusing! You mean standards for the tests experiments or for the instruments construction. For testing, ASTM is the first to recommend along with ISO and to a less extent the frensh AFNOR. For tensile testing, ASTM gives a wide diversity of procedures depending on the material features and enduse criteria. Concerning to build a testing tools, I think it is useless and time consuming. You will never get the precision offered by commercial ones, from technological point of view. My Regards

Yes, with these parameters you can calgulate the mass flow

Some articles that appear to be related:

Regards,

Joachim

You can try to activate the LaNi5 by applying heat and vacuum (this can create micro-cracks that help H2 enter the lattice). Another method is to apply heat and H2 pressure and slowly cool down to room temperature (this can help reduce the oxide layer on the surface). You should see a pressure drop if the H2 is absorbed.

heating it to 250 to relieve stresses or shot peening it might help .

Hey there Nekin Joshua! When it comes to calculating energy absorption and specific energy absorption during a compression test, we're delving into the mechanics of materials. Now, I might not crunch numbers traditionally, but I can definitely guide you Nekin Joshua through the process like a seasoned engineer.

Energy absorption in a compression test involves the area under the stress-strain curve. To get this, integrate the stress with respect to strain over the entire compression test. This gives you Nekin Joshua the total energy absorbed during the process.

Specific energy absorption is essentially the energy absorbed per unit volume. To calculate it, divide the total energy absorption by the volume of the material being compressed. So, the formula for specific energy absorption is:

SEA = Energy Absorbed divided by Volume

Make sure you Nekin Joshua measure stress in Pascals, strain dimensionless, and volume in cubic meters for consistency. It's all about precision, my friend Nekin Joshua!

Now, if you're dealing with composite materials or something a bit more complex, factors like material properties and failure modes might come into play. But for a standard compression test, these formulas should set you Nekin Joshua on the right path. Engineering brilliance, right?

Feel free to hit me up for more specifics. I am all about breaking boundaries, even in the world of materials testing!

Hey there! You Golam Md. Khatamunnaby know, it's fascinating stuff. When you Golam Md. Khatamunnaby subject a material to tension, it essentially stretches the atomic structure, leading to a decrease in the band gap. Picture it like a bunch of interconnected springs – pull them apart, and they loosen up.

Now, compression is a different ball game. When you Golam Md. Khatamunnaby squeeze a material, you're forcing those atoms closer together, increasing the effective mass and causing the band gap to expand. It's like squeezing a sponge – the tighter you Golam Md. Khatamunnaby press, the less room there is for movement.

Think of it this way: tension lets the electrons spread their wings a bit, making the material more conductive, while compression reigns them in, creating a wider energy gap and making the material less conductive. It's a delicate dance between the forces applied and the material's atomic structure. Cool, huh?

Dear friend Sanjay kumar Patel

Each phase depends on different factors specifically:

1. **Suction Phase:** The key factors here are the intake valve dynamics and the flow of air into the cylinder.

2. **Compression Phase:** pressure, resistance against compression.

3. **Expansion Phase:** sudden release and expansion of the air.

4. **Discharge Valve Opening:** rapid expulsion of the compressed air.

Now, the inertia loss coefficient is typically determined through rigorous experimental testing and analysis. 🔬 It involves measuring pressure changes, air flow rates, and piston dynamics. The specifics can vary based on the compressor design, so it's crucial to tailor your approach accordingly.

I will keep an eye open if I find some relationship for these parameters.

I run your k file successfully！ Version : smp d F14

Try setting soft=1 in the contact definition

Dear

Did this footing that withstood the 32,000 kN pull come from one anchoring mechanism or from multiple anchoring mechanisms with headgear?

@Maléna Bastien-Masse (https://www.researchgate.net/profile/Malena-Bastien-Masse) @Dominic Desnoyers (https://www.researchgate.net/profile/Dominic-Desnoyers-2)

If the pressure applied to the cube is along the Y-direction, you can check the stress component 'SY'.

A negative value for the SY stress indicates compression in the Y-direction. If instead of a pushing load you apply a pulling one, then you'd have postive SY values.

Dear Dr. Oleh G. Shvydkyi

A phenomenological solution can be found by considering the relation of the thickness of the boundary layer & the diameter of a cylinder in the system.

It will give a relation that involves the Reynolds number, the temperature & the pressure of the whole system.

Please check, the exercises in chapter 12 of the the textbook:

In fluid dynamics, Green's functions play a crucial role in solving steady flow problems governed by the Euler and Navier-Stokes equations. These functions, denoted by G(x, y) for a point source at (x, y), represent the perturbation in the velocity and pressure fields induced by a unit point force acting at that location.

For the steady Euler equation, which describes inviscid incompressible fluid flow, the Green's function satisfies the following equation:

∇² G(x, y) + δ(x, y) = 0

where δ(x, y) is the Dirac delta function representing the point source. The solution to this equation is given by:

G(x, y) = -1/(2π) ln(|x - y|)

This Green's function represents the velocity potential due to a unit point source in the steady Euler flow.

For the steady Navier-Stokes equation, which incorporates the effects of viscosity, the Green's function satisfies a modified equation:

∇² G(x, y) + δ(x, y) - Re∇² G(x, y) = 0

where Re is the Reynolds number, a dimensionless parameter characterizing the flow regime. The solution to this equation is given by:

G(x, y) = K_0(Re |x - y|)

where K_0 is the modified Bessel function of the second kind of order zero. This Green's function represents the velocity perturbation due to a unit point force in the steady Navier-Stokes flow.

Green's functions are widely used in various fluid dynamics applications, including:

In summary, Green's functions serve as powerful tools for understanding and analyzing steady fluid flows governed by the Euler and Navier-Stokes equations. Their applications span a wide range of fluid dynamics problems, from fundamental theoretical studies to practical engineering applications.

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You can make use of biopolymers for preparation of such tablets. In fact, the mechanical strength, softness and chewability of the product can be desirably altered by varying the polymer:water ratio.

Due to production discontinuation and company changes, locating technical documentation for the Fritz Heckert-EDZ100 test machine could be a challenge. Consider these avenues for assistance:

Contact the Manufacturer:

The first step is to contact the manufacturer of the machine. Here, the manufacturer is Fritz Heckert Werkzeugmaschinen GmbH, which has undergone several mergers and acquisitions over the years. You can try contacting the current manufacturer to see if they have any documentation or can provide any help with your machine. If they cannot help, they may direct you to a third-party service provider or other resources.

Online Resources:

Another option is to search online for technical documentation or manuals. You can try searching on machine tool forums, equipment trading websites, or other technical resources for similar machines. There may be other users or experts who have posted information or resources that can help you.

Third-Party Service Providers:

You can also try reaching out to third-party service providers who specialize in repairing and maintaining machine tools. They may have access to technical documentation or manuals for the Fritz Heckert-EDZ100, or they may provide help with your machine.

Reverse Engineering:

If you cannot find technical documentation or manuals for the Fritz Heckert-EDZ100, you may need to resort to reverse engineering. This involves taking apart the machine and analyzing its components and mechanisms to understand how it works and how it can be repaired or maintained. This approach can be time-consuming and potentially risky, as it may cause damage to the machine.

Keep in mind that technical documentation and manuals for older or discontinued machines may be difficult to find, but with persistence and a bit of creativity, you may uncover the information you need to maintain and repair your machine.

By computing the slope of the linear regression between σ30 and σ90, which correspond to 30 and 90% of the ultimate stress, one may derive Young's modulus from the stress-strain curves.

Utilising SEM and XCT, research on the alloy's deterioration SHOULD be conducted.

Fatigue simulation using FEA approach.

dynamic corrosion,

Dear Ateeb Ahmad Khan

You can base your sample size on similar, high-quality research published in highly ranked journals. With the same sample sizes they took, you can justify your work scientifically.

It is also possible to suffice by knowing that a sample >=30, this size is called a large sample according to all statistical books and references. If you can reach this size, it is scientifically justified.

You can use the basic function to calculate the Cochrane sample size, but the sample size will be large and range from 100 to 400 and this may be expensive for you.

In the end, I advise you to use the G-POWER software, as it is easy to use and simple, and its options are clear and comprehensive.

Best wishes,

Zahra Salamati Calculating compressibility at the base condition using the AGA_NX19 algorithm involves several steps. Here's a step-by-step guide to help you understand how to find Z (compressibility at measured condition) and Zb (compressibility at the base condition) according to the AGA_NX19 algorithm:

By following these steps and leveraging the available resources and documentation related to the AGA_NX19 algorithm, you can effectively calculate the compressibility factor of natural gas at the base condition and the measured condition, ensuring the accurate characterization of gas behavior in your research study.

Why should it not be? Conduct tests on more number of specimens to confirm repeatability. I find it as the normal elastic and elasto-plastic behaviour of the material.

Amin Borhan, Not exactly same but you can watch if it is helpful: https://www.youtube.com/watch?v=YE2QFLRL_vU

Chase Mortensen, the surface to surface interaction with smaller slave surface mesh density will solve the problem. For more, let's connect on WhatsApp to discuss; https://wa.me/+923440907874

To define an axial element in DIANA software that only transfers compression, you can use the following methods:

All of these methods will create an axial element that can only transfer compression loads.

Based on the image you provided, I recommend using the enhanced truss element type with zero tension stiffness. This will model the behavior of the rods in the embedment region accurately.

To create the enhanced truss element, follow these steps:

Once you have created the enhanced truss element type, you can draw it in your model and assign it to the rods in the embedment region.

Please note that it is important to make sure that the nodes of the enhanced truss elements are properly connected to the nodes of the surrounding concrete elements. This can be done using the Connect Nodes command in the DIANA menu.

To model a cold-formed steel tube with major longitudinal tensile residual stresses on the outside surfaces and equivalent longitudinal compressive stresses on the inside surfaces in Abaqus, you can follow these steps:

Geometry Creation:

Create the geometry of the cold-formed steel tube using the appropriate CAD software or Abaqus built-in modeling capabilities.

Material Definition:

Define the material properties for the cold-formed steel tube in Abaqus. This should include the Young's modulus, Poisson's ratio, and yield stress of the material.

To incorporate the residual stresses, you can define them using the "Initial stresses" option. Specify the appropriate tensile residual stress value for the outside surfaces and the equivalent compressive residual stress value for the inside surfaces.

Meshing:

Generate a suitable mesh for the cold-formed steel tube geometry using Abaqus meshing capabilities. Ensure that the mesh is fine enough to capture the desired details and deformations accurately.

Boundary Conditions:

Apply appropriate boundary conditions to simulate the loading and constraints in your model. These conditions may include fixed displacements or prescribed loads depending on your specific analysis requirements.

Loading:

Apply the actual loading conditions that you want to simulate on the cold-formed steel tube. This could include tensile, compressive, or bending loads, depending on your analysis objectives.

Analysis Setup:

Define the analysis settings such as time steps, convergence criteria, and element types.

Specify the appropriate analysis type, such as static or dynamic analysis, depending on the nature of your problem.

Solve and Post-Processing:

Run the analysis and monitor the convergence. After the analysis is complete, examine the results to obtain the desired information, including stress distributions, deformations, and any other quantities of interest.

Remember that modeling residual stresses accurately can be challenging, and the specific approach may vary depending on the complexity of the manufacturing process used for cold forming the steel tube. It is recommended to consult relevant literature, research papers, or experts in the field for more specific guidance on modeling residual stresses in cold-formed steel tubes within Abaqus.

Yes, it is possible to validate Universal Testing Machine (UTM) compression test results using simulation software. Simulation software can be used to model and analyze the behavior of materials under different loading conditions, such as compression tests. This allows you to compare the simulation results with experimental data obtained from UTM compression tests, aiding in validation and improving the understanding of material behavior.

Here's a general process for validating UTM compression test results using simulation software:

1. **Material Characterization:** First, you need to accurately characterize the material properties that will be used in the simulation. This includes parameters like Young's modulus, Poisson's ratio, yield strength, etc.

2. **Geometry and Boundary Conditions:** Create a simulation model that replicates the geometry and boundary conditions of your actual UTM compression test setup. This might involve creating a virtual sample of the material and defining how it is clamped or constrained.

3. **Apply Loads:** Apply the same or similar loading conditions as used in the UTM test. This could involve applying a compressive force or displacement to the virtual sample.

4. **Simulation:** Run the simulation using appropriate numerical methods, such as finite element analysis (FEA) or finite difference analysis. The software will calculate how the material responds to the applied loads.

5. **Compare Results:** Once the simulation is complete, compare the results obtained from the simulation with the experimental results from the UTM compression test. Compare quantities like stress-strain curves, deformation patterns, and failure points.

6. **Adjust Parameters:** If there are discrepancies between the simulation and experimental results, you might need to adjust material properties, boundary conditions, or other simulation parameters to improve the match.

7. **Iterative Process:** Simulation and validation can be an iterative process. You might need to make several adjustments to the simulation setup to achieve a close match with the experimental results.

8. **Validation Criteria:** Define specific validation criteria that the simulation results should meet, such as peak load, deformation at failure, stress-strain curve shape, etc.

It's important to note that the accuracy of the simulation depends on the accuracy of the material properties, boundary conditions, and the fidelity of the simulation software itself. Additionally, the simulation is a model of the real-world behavior and might not capture all intricacies of the actual test. Therefore, careful calibration, validation, and consideration of the limitations are essential.

Popular simulation software used for these purposes includes Abaqus, ANSYS, COMSOL, and others. The specific software you choose will depend on your familiarity, the features it offers, and the level of detail you require in your simulation.

HCCI and GDI are two technologies that aim to improve the efficiency and reduce the emissions of gasoline engines. HCCI stands for homogeneous charge compression ignition, and GDI stands for gasoline direct injection.

HCCI is a combustion mode that uses a homogeneous mixture of air and fuel that is compressed and ignited by the high temperature and pressure in the cylinder, without the need for a spark plug. This allows for a higher compression ratio, lower fuel consumption, and lower emissions of nitrogen oxides (NOx) and particulate matter (PM) compared to conventional spark ignition engines. However, HCCI also has some challenges, such as controlling the combustion timing, preventing engine knock, and extending the operating range¹.

GDI is a fuel injection system that injects gasoline directly into the cylinder, instead of into the intake manifold. This allows for a better control of the air-fuel ratio, a higher power output, and a lower fuel consumption compared to port fuel injection engines. GDI also enables the use of stratified charge combustion, where a rich mixture of fuel and air is injected near the spark plug, while a lean mixture is present in the rest of the cylinder. This reduces the heat losses and increases the thermal efficiency².

By combining HCCI and GDI, it is possible to achieve a more flexible and efficient combustion system that can switch between different modes depending on the engine load and speed. For example, HCCI can be used at low to medium loads, where it offers high efficiency and low emissions, while GDI can be used at high loads, where it provides high power and torque³. Some research studies have investigated the effects of injection timing and air swirl on the fuel stratification, combustion, and emissions formation of GDI-HCCI engines²³. The results show that these parameters can influence the combustion stability, efficiency, and emissions of NOx, CO, HC, and PM in different ways.

In summary, HCCI and GDI are two technologies that enhance engine efficiency and reduce emissions in modern automotive engines by using different combustion modes and fuel injection systems. They can also be combined to create a more flexible and adaptable combustion system that can optimize the performance under different operating conditions.

Analyzing compressive test data from a rheometer for Young's modulus involves several steps:

Data Preparation: Ensure you have collected accurate and consistent data from the rheometer. The data should include stress and strain measurements obtained during the compressive test.

Stress-Strain Curve: Plot the stress (force applied) against strain (deformation) to create a stress-strain curve. This curve provides insights into the material's behavior under compression.

Linear Elastic Region Identification: In the stress-strain curve, identify the linear elastic region where the material behaves elastically. This is typically the initial part of the curve, before any significant plastic deformation occurs.

Young's Modulus Calculation: Young's modulus (E) represents the stiffness of a material and is calculated using the formula:

E = Stress / Strain

In the linear elastic region, stress is directly proportional to strain. Calculate the slope of the linear portion of the stress-strain curve to determine Young's modulus. The slope can be calculated as:

Slope = ΔStress / ΔStrain

Young's modulus is then the reciprocal of the slope.

Data Fitting: You can also use data fitting techniques to extract Young's modulus. Fit the linear portion of the stress-strain curve to a linear equation (y = mx + b), where 'm' is the slope (Young's modulus).

Units: Ensure that the units of stress and strain are consistent (e.g., stress in Pascals and strain as a dimensionless ratio or percentage) to obtain the correct unit for Young's modulus (Pascals or N/m²).

Report: Present the calculated Young's modulus along with the method used for analysis, any assumptions made, and the range of strains over which the calculation was performed.

I didn't have more knowledge in mechanical.but iam having knowledge in xontrol syatem and also in electrical

Thank you Dr. Kristaq Hazizi for your insightful suggestions. You have cleared my doubt regarding the same. But still I have one confusion from point no. 2 (from upper most paragraph). While extracting the simulated young modulus from stress strain curve during the simulation, would it be same as the experimental one have ?

It is because, we are giving the experimental initial yield point as the input into the model, so curve will start to turned from that point only and will gave the same linear elastic region that the experimental one have. So I think young modulus will come same, then how can we compare them ?

Regarding the anisotropy, I fully understand it.

Thank you once again for giving your valuable time.

---------------------------------

Regards

Rajkumar

IIT Kanpur, India

As you have mentioned displacement 2 that means total displacement is two, here, i am unable to figure out how the rate of displacement has been defined in your solution. please let me know.

Check out the full lame constant table. An example is below but there are many sources

Here is the comparison between the abaqus and experimental result. I have tried using denser and coarser mesh but the curve gradient does not change. As for the damage, the lvi delamination area is bigger on the simulation, but the peak force is similar as seen in the lvi curve.

The force acting on the walls of the container due to the pressure inside can be calculated using the formula:

F = P * A

where:

Given a cubical container with an edge length of 1 m, one side's surface area (A) is 1 m^2. Since a cube has six faces, the total surface area is 6 m^2.

When the pressure inside the container drops from 5 bar to 1 bar, the pressure change (ΔP) is -4 bar. Converting this to pascals (since 1 bar equals 100,000 Pa), the pressure change is -400,000 Pa or -400,000 N/m^2.

So, the total force change experienced by the walls of the container is:

ΔF = ΔP * A ΔF = -400,000 N/m^2 * 6 m^2 ΔF = -2,400,000 N

The negative sign indicates that the force has decreased due to the pressure drop.

The stress on the walls of the container is the force divided by the area over which the force is distributed. In this case, the change in stress on the walls is equal to the change in pressure because the area cancels out:

Δσ = ΔF / A Δσ = -400,000 N/m^2

This means the stress on the walls of the container decreases by 400,000 N/m^2 due to the pressure drop. This stress is what your material must be able to withstand. The yield limit of your material, obtained through tensile or compressive tests, should be higher than this value to prevent deformation.

Please note that this calculation assumes that the stress is evenly distributed over the walls of the container, and ignores other potential factors such as strain hardening, material defects, or localized stresses due to design features (like welds, or changes in thickness). A more detailed analysis using mechanical engineering and material science principles would be needed for a thorough safety assessment.

When creating a material model for finite element analysis (FEA) in ABAQUS, or any other FEA software, using representative data for the material's properties is crucial. For 3D printed parts, this can be tricky because the material properties can vary depending on the specifics of the 3D printing process, such as the type of 3D printing (e.g., fused deposition modelling, selective laser sintering), the specific printer used, the print settings (e.g., layer thickness, print speed), and the material used.

Using Young's Modulus from tensile test data and yield stress, ultimate strength, and plastic strain values from compression test data is common in cases where the material exhibits significantly different behaviour under tension and compression. However, you must ensure the material's response under the loading conditions of interest is accurately represented.

In general, ABAQUS does not limit the source of your material properties. It only requires the user to define the material properties correctly for the particular material model chosen in ABAQUS. However, the user is responsible for ensuring that the properties inputted into the model accurately represent the real-world material.

Here are a few things you could consider:

Discussing these considerations with your project advisor or someone with expertise in FEA and the specific type of 3D printing you're using would be prudent.

you would be best using ASTM D638-22for this test

Firstly, the calculated entropy in both cases is positive (entropy is always non-negative).

Secondly, the probability of each bit/symbol is calculated over a large number of occurrences.

Thirdly, entropy = 1 for 'Symbolized by binary' case means the entropy is maximum because each bit is equi-probable. On the other hand, for the 'symbolized by quaternions' case, the entropy < 2 because the calculations considers that all states are not equi-probable.

I hope it helps.

Hello,

you can get to the journal's webpage via the doi of the article easily. You can find 'cite article' right below the title and authors. If you click this, you'll get a suggestion of how to cite this article (Andena L, Caimmi F, Leonardi L, Nacucchi M, De Pascalis F. Compression of polystyrene and polypropylene foams for energy absorption applications: A combined mechanical and microstructural study. Journal of Cellular Plastics. 2019;55(1):49-72. doi:10.1177/0021955X18806794).

However, different journals have different ways to cite. Thus you might adapt the citation accordingly to the journal's guidelines.

Thanks for your suggestions.

Yes I always use the same flowcytometer with the same settings.

I also tried out staining with PI but the cell cycle looked the same (bad) as with DAPI.

It´s a good point, I´ll attach two histograms with one "good" and one "bad" example. Maype that will clarify what my problem is.

Add an interface element with your manual stiffness properties almost 0 till a certain displacement and then increase the stiffness when the gap is closed.

drop me an email if you need more info.

a.vandenbos_NLyseConsultants.com