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Bearings - Science topic
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I am looking to design and further running simulations and analyse a low speed shaft of a typical wind turbine. In particular I am looking to design the shaft diameter and length and any other connection components such bearings, keys and so on, for a given torque and rotational speed requirement in a transmission system of a wind turbine. Do you recommend any good software to run FEA simulations for validation analysis purposes.
Any suggestions or comments, I will much appreciate.
What is the formula for the calculation of Reynold number for the thrust and Journal bearing.
In this formula, Re = (ρvD)/μ
- What is the V(mean velocity) and D (characteristic dimension) for thrust and Journal bearing?
- What is the limiting value of Reynolds number for the flow to be laminar or turbulent?
I have a subroutine for Elastomeric bearing. I want to use it for simulation in ABAQUS. For that, I need to define two noded UEL and assign them between two 3d Objects, as shown in the attached figure (UEL.PNG). As UEL can define only in the Input file, I am confused about how to assign the UEL between two objects. can anyone help with this? I have also attached the input file for reference.
I used deep groove ball bearing instead of journal bearing in scroll compressor, but it increases noise by 3-5 dB.
The simple bridge simulation was performed in ABAQUS to evaluate the seismic response using Lead Rubber Bearings. The bearings were modeled using connector elements in Abaqus. I tried to enter the bilinear experimental data in Plastic behavior (Kinematic Hardening) half cycle data option in Abaqus. After simulation i obtained this irregular shape hysteresis. The hysteresis is constructed with reaction force and displacement at the Lead Rubber Bearing node.
Please see the attached pictures.
I'm working on a design for a solar panel fixture for a capstone project. I have a panel weighing 20 lbs and with the frame, it's overall 35 lbs. The panel assembly will be mounted on a rod (48in long) using 6 routing clamps, and the rod has 2 bearings attached to the ends. I want to determine how much torque will I need to rotate this solar panel assembly, therefore using that to determine the size of the motor. And, to determine the radial and axial load to choose the right bearings. The speed will be 5rpm. Would be much appreciated if someone can provide support.
Math problem We have a six-storey load-bearing structure with a floor area of 10X10=100sq.m with nine walls of cross-section 0.30X2.5m with 5X5m canvas Beams with a cross-section of 0.50X0.25m and slabs with a cross-section of 0.15m Height of each floor 3.00m If a very strong earthquake with a swing amplitude of 0.15m, a displacement of 0.30m and a full swing of 0.60m with a frequency of 2Hz strikes the structure, what will be the acceleration, shear base (inertia) and overturning moment of the construction and of each wall separately in order to juxtapose at the uppermost edge of the walls a greater moment of stability coming from the ground so that it does not topple over; Solution 1. Ground acceleration in ( g ) ( 1g=9.81m/sce2 ) a=( -(2*π*2)^2 * 0.15 ) / 9.81 a=3.14x2=6.28x2=12.56X12.56=157.754X0.15=23.6631/9.81=2.41g natural earthquake. Floor cubes Slab 15m3, beams 7.5m3, walls 15.87m3 Total cubic floor 38.37 m3 The six floors have 6X38.37= 230.22m3 Specific weight of reinforced concrete 2450 kg/m3 The 230.22 m3 of the bearing X the specific weight of the reinforced concrete 230.22X2450=564039kg or 564 tons of mass and the six floors together except the bases which are 50m3 Masonry 8 tons / floor The 6 floors 8X6 = 48 tons Floor covering weight 75kg/m2 X 100m2 the floor =7.5ton The six floors 6X7.5= 45ton Payload per floor 7.5ton The six floors 6X7.5= 45ton Total mass of six floors in ton = 702ton 2.Inertia force and shear base F=m.α 702tonX23.6631= 162908 kN Each of the 9 walls has a shear base of 9/162908= 18100 kN 3. Overturning moment of each wall separately The inertia on the six floors is 702ton One floor corresponds to inertia 6/702= 1117 kN Each wall of the 9 walls of the floor has an inertia of 1117/9=124kN What is the overturning moment on each wall of the six-story structure when the height of each floor is 3.00m? First we add all the heights (18+15+12+9+6+3) = 63 m and multiply them by 124 kN= 7812kN Then we divide 7812kN by the dimension of the width of the base of the wall which is 2.5 m and it comes out 7812kN by 2.5 = 3125 kN The overturning moment of the wall is 3125 kN Must Overturning Moments i.e. 124*(18+15+12+9+6+3) <(smaller) than the Stability Moment imposed by the force coming from the ground It follows that the stability moment coming from the ground must be greater of 3125 kN to prevent the wall from overturning and creating secondary moments in the cross-sections around the nodes. That is, Must Stability Moment > 3125 kN These moment forces must be received by the cross-sections around the nodes, or by my mechanism itself, completely freeing in this way the cross-sections around the nodes to generate counter-moments. Of course, due to the elastic deformation from bending, in reality the mechanism and the cross-sections around the nodes and the infills will receive the overturning moment of the wall together. The geotechnical study is the second serious calculation. Whether I get a deal is another factor. Here I reckon that the compaction of ground construction is a given. I am experimentally dealing with a compaction mechanism that converts vertical axial compressive and tensile forces into compressive forces and deflects them towards the borehole slopes.
I want to model a 2d six-story steel moment frame containing the combination of base isolation and viscous damper in the base. I want to know which element is more relevant to my goal and also how I can use it in opensees.
I attached the picture of the model below.
Hello everyone, I'm doing modal analysis of a rotorshaft with a disk. My model includes two bearings fixed between the shaft and two supports. I already know the stiffness matrix coefficients for my bearings so I want to know how to model the bearings.
I tried to create bearings with the "bearing body to body" tool in "connection" scoping the reference to the support face and the mobile to the shaft. What kind of boundary conditions do I have to add? I used a remote displacement condition for each bearing constraining rotation and translation about the Z axis (bearings are in X-Y plane) but I got the warning that remote displacements share one or more faces/edges and the model might be overconstrained. Why is it wrong? Am I not supposed to use a remote displacement for each bearing?
I have to model a bearing in a large assembly instead of taking all the solid body into the analysis in ANSYS. Here I have roller bearing at a wheel location.
Is it possible to model using 1D element and give them a stiffness or any joints to be used to define the stiffness and other constrains
Access to firearms is a well documented risk factor for suicide. Regardless of why someone might have one or more of AR-15 or similar weapon, there's no disputing their inherent lethality. Irrespective of whether or not they are ever employed as a means of suicide, does their implicit lethality affect the nature/intensity of suicidal ideation and the likelihood that ready access to one may significantly increase the risk of using any firearm in a suicide attempt? Does this have any bearing on the suicidality manifested by perpetrators of mass shootings? If access to firearms creates a baseline capability for suicide, does access to potentially much more deadly firearms enhance that capability?
My question is related to the dimensions of the dead layer of HPGe detectors for MCNP work. Is it normal that the upper dead layer formed is larger than the side dead layer? Or vice versa? Or are the two layers the same dimensions? Bearing in mind that the dimensions of the manufacturer specifications in the detector certificate that the upper and side lid are the same dimensions.????
I would like to know the reasons for preferring Hansen's method over Vesic method, although in both methods the same range of answers are determined in most of the cases.
I understand there will be exact multiple of fundamental frequency based bearing rotation with respect to fundamental, based on gear rotation with respect to fundamental. But what exactly means for multiples of bearing rotations, multiples of blade passes like 1x, 2x, 3x etc.,
For instance if one wants to assess effects of Malaria on pregnancy outcomes on pregnant mothers with Malaria infection.
Bearing in mind that they have to collect data from patient case notes of these pregnant mothers who had Malaria infection and were previously admitted and delivered their babies at a particular hospital in the past
I have a problem in my organization, which is that some department managers show a disagreement within them, and I have the desire to write a research that addresses this problem, which has aggravated. What is your opinion about choosing the title of the article, bearing in mind that the titles are modern and somewhat unpopular, can you help me, brothers and sisters, in that...
Salam Abduljaleel Alramdhan
I have been trying to generate a substructure in ABAQUS for a big diameter roller bearing. I have used two reference points, one each for inner and outer raceways to couple the inner and outer raceway surfaces. I have two steps in the analysis. The first step is Frequency followed by Substructure generation step. The analysis runs fine till the end of first step and calculates the eigen frequencies. When the second step starts, following error message appears.
" Element 439473 requires more than 2GB of memory for storage"
Element 439473 is just a point on the outer raceway and it is not used in any of the couplings. I have used continuum distributing couplings for coupling the reference points and the raceway surfaces. Following error also pops up after the element error.
***ERROR: An attempt to access admc buffer has failed. Any help would be truly appreciated.
Thanks in Advance.
What could be the effect of Waste Plastic irregular chips on the bearing capacity of compacted Soils? And If the Plastic is cut into regular shaped stirrups then how different will be the resulting improvement, if any?
Perhaps surgical techniques have changed and some are allowed but a good proportion are not allowed to weightbear. May I know the reasons or indications to keep a patient non-weightbearing? Noted a previous discussion on load bearing and sharing differences a few years back. Noted for IM Nailing, which is load sharing, patients are allowed to weight-bear early. Noted also that a dynamic hip screw is load bearing but weight bearing is allowed since stability is achieved. Thanks!
Generally, in literature (from what I've read), to monitor conditions of mechanical rotating drivetrains connected to an electric motor are used accelerometers. Or in the case of short drivetrains also the current signals can be significant to detect anomalous torque load oscillations related to a mechanical fault. In the case of nonstationary conditions (not constant speed of the electric motor), the Computed Order Tracking (
Article Analysis of computed order tracking. Mech Syst Sig Proces
) is a technique that is able to extract Orders of the rotor speed in vibration signals even when the speed change over time. In that way, is possible to relate each component that rotates at a known, fixed rate with respect to the motor rotor, and detect unwanted vibrations.
Could I apply the same technique for electric signals? If I have an electric motor with a speed reducer attached with a damaged bearing running at varying speeds, once acquired the one-phase current signal and the rotor speed feedback, if I apply a resampling of that signal with respect to the angle (as in the Computed Order Tracking for vibration signals), would I be able to detect speed Orders that can be related to the defecting bearing? In literature, there are no papers that apply COT to electric signals (or at least I haven't found it), which is the reason? This technique would be ineffective? There are some resolution limits? Or depends on the fact that electric signals are rich in frequency content related to the supply and mechanical oscillations are too weak to be detected?
If we want to look at the universe we can not ignore the force that moves everything.
No one knows where this force that moves molecules and atoms comes from.
But we do know some physical properties of power.
Power = energy, which changes form, but is not lost.
Two equal and opposite forces, balance.
The force is diverted, that is, it changes direction
The force is broken down into components or multiplied by component forces, with the lever arm.
Power is everywhere but it is invisible and appears only from the effect it causes.
In the science of civil engineering there are static forces which are managed in order to achieve a balance of forces, and non-linear variables which are caused by the displacement of the ground in a seismic event.
When mass is stationary it is easier to calculate the forces of mass and contrast opposing forces to achieve equilibrium.
When an earthquake occurs, additional forces appear which are often three times the size of the static mass loads, because they are multiplied by the magnitude of the ground acceleration, the duration of the earthquake, and the height of the mass X its weight
These forces on the load-bearing structure of the building multiply, change their direction, and diffuse into all areas of the cross-sections of the structure, which are weak and can not react, creating equilibrium forces.
The result is that there is a breakage and collapse of the structure.
There are six solutions to balance and consume energy.
a) To increase the dynamics of materials without increasing their mass which is a factor of multiplication of intensities.
b) To convert the force of an earthquake from kinetic to thermal
c) To reduce the acceleration of the ground to be transferred to the construction using horizontal seismic insulation (bearings)
d) To make a rubber unbreakable bearing body from rubber or sponge.
And two other systems you do not know are ...
e) To put independent parts of the construction, to collide with each other, on elastic joints and in this way one part to neutralize the forces of the other.
g) To deflect the forces from the structure into the ground before they multiply through the lever mechanism and diffuse over the cross sections of the bearing body.
All but all of these systems that I mentioned contribute to the response of the construction to the seismic shifts and are concentrated in the anti-seismic design that I designed, for the first time in the world and is in this video.
I am doing my project on journal bearing, it will be helpful suggest about the matlab code on solving reynolds equation by FDM.
In Taper Roller Bearing and Cylindrical Roller Bearing of different sizes, what is the process to test/check the noise and vibration in the assembly. If any standard process available please do share.
In this research, I am trying to replace the traditional bricks and concrete because these materials have much weight causes increasing the weight of the overall structure.
The vibration sensor (e.g. accelerator) is commonly used to monitor the vibration signal of a bearing for condition monitoring and fault diagnosis. If there any Standard for bearing vibration signal monitoring?
A lot of deep learning algorithms (i.e. CNN, RNN, DBN, etc.) for bearing lifespan prediction have been reported. Each one has its respective pros and cons. But is there any technique that has been well applied in real industrial applications?
The vibration caused by a bearing is usually used as a key parameter to evaluate the health and operating conditions of the bearing. To achieve this purpose, a threshold value of vibration signal to distinguish the healthy and abnormal bearing is often required. How to set/determine a threshold value of a bearing in a specific application?
I am an undergraduate electrical engineering student researching on the application of motor current signature analysis for fault detection in three-phase induction motors. I plan to use LabView simulation tool. However I do not have a physical motor that I can use to create faults to it. Now My question is does LabView simulation tool provides an option for creating faults such as stator fault, rotor fault and bearing fault on the virtual motor? Your answers will be highly appreciated
Bearings are one of the key components in many industrial applications. Research on bearings has been going on for many years but has not stopped. What are the current and future research hotpots for bearings?
when the analysis is done by the Axisymmetry model, the out put of force vs displacement is obtained by the kN/rad. simply we multiply 2pi and get force in kN. in this case square footing (150x150mm) is half.
but when the same analysis is done the Plain stain model, the output is obtained kN/m. so which length of width is multiply to get force or how to get bearing capacity. use square footing 150x150
pictures are attached. please explain.
Generally CHO (DHFR -ve) cells on transfection with plasmid bearing DHFR gene + Gene of Interest and upon addition of MTX only thoose cells which take up plasmid (containing DHFR + Gene of Interest ) will survive others will die.
My doubt 1 is : Generally DHFR is involved in De novo synthesis of Nucleotides, then how the nucleotides are synthesized in CHO (DHFR -ve ) cells?
My doubt 2 is : CHO (DHFR -ve ) cells lack DHFR so they couldn't use De novo pathway for nucleotide syntheis but they can use salvage pathway, then after transfection with Plasmid (containing DHFR + Gene of Interest) all the cells will survive due to operation of salvage pathway, now how to distinguish between the transfected cells vs Un transfected cells.
I'm confused with this DHFR-MTX selection system, could someone please help me to understand this concept, Also please share any referance material.
Bearings are one of the critical components in rotary machines such as motors, wind turbines, helicopters, automobiles, and gearboxes. Most of these machine failures are caused by bearing faults. Thus, being able to detect bearing faults and predict remaining useful life (RUL) can help to provide advance failure warnings, plan the maintenance schedule, and avoid catastrophic failures. What are the most common technologies for bearing fault detection and RUL prediction?
Bearings are one of the critical components in rotary machines such as motors, wind turbines, helicopters, automobiles, and gearboxes. Most of these machine failures are caused by bearing faults. Thus, being able to detect bearing faults and predict remaining useful life (RUL) can help to provide advance failure warnings, plan the maintenance schedule, and avoid catastrophic failures. Based on this, what are the most prevalent methods for bearing degradation detection and remaining useful life prediction?
When the proposed water-lubricated textured groove thrust bearing is under high speed, the initial cavitation number will increase, so the cavitation effect should be considered when modelling.
The previous research has established that cavitation obviously exists in the textured bearing, including thrust bearing under hydrodynamic lubrication and mechanical seals.
the bearing capacity from hardening soil method and mohr-columb method is higher than theoretical method of Meyerhoff and Hansen method
For the reaction between trifluroacetylacetone and primary amine, on which carbonyl group the C=N will form? The one that bearing methyl group or the other that bearing trifluroacetyl group?
I want to find the deflection of a beam which has a bearing support at the centre and two forces acting at the end of the beam. What kind of support can I approximate for the bearing support, for method of unit load.
We want to choose specific bearing between all standards like SKF, KOYO, etc. Is there a book or excel file for finding it. For example we have ball bearing with this diameters 25X30X14. How we can find it between all standards?
The Land developer in the south Asian countries performs mass rehandling of the earth to convert barren lands into housing socities. There are uncontrolled filling as deep as 30 ft. The filling material is mostly of Silty Clay type and it is in a relatively dry state. SPT N values are generally in the range of 4-10.
What could be the most effective and economical method to improve the bearing capacity of such fillings?
i know the data is available under this website
but i am unable yo understand how to use in the coding?
Now I'am doing a simulation by using ANSYS FLUENT for the surface texture study of journal bearing. As you can see in the picture fluid area or journal bearing with surface texture...Unfortunately the result that i get which is maximum pressure of the fluid is lower compare with smooth/plain journal bearing. As i read in the journal, supposedly the result is higher for the surface texture of journal bearing as compare with plain bearing.. Any idea guys what types of surface texture i need to design, or the location or the parameter that i need to adjust in order to get the final maximum pressure value is higher as compared to plain journal bearing.Thanks
It is required for the stability analysis of bearing.
Large scale bearings especially that uses in wind turbines gearboxes exhibit transient loading that cause premature failure, I am working on estimating the percentage of bearing life reduction due to transient loading to predict the bearing life depending on the number of transient loading occurrence and their levels.
First I would like to thank you all for the possible valuable suggestions. I have some confusion. I am doing roll bearing fault diagnosis using DWT and unsupervised machine learning algorithms. I am going to use the data set from FEMTO bearing repository but here is my confusion.
1. The accelerometer data was collected using 2 accelerometer arranged with perpendicular direction. so that I have dual direction accelerometer data. I am going to use DWT for signal pre-processing and feature extraction , it is feasible to take stastical features for both acceleration data for each frequency sub-bands?
2. The data repository was purposefully performed to determine the Remaining Useful Life (RUL) of bearing. so there is no training data for fault characteristic frequencies. How can I make training data set for each fault type associated with bearing anomalies. the link how the experiment was done is attached in case some one need it for test bench mark.
Analyzing a strip footing over granular soil having C= 2kPa & phi = 36 with density as 16 kN/m3, Mohr-Coulomb as soil model. Geogrid stiffness as 200 kN/m. Please suggest any changes.
Looking at the nmr spectrum of p-formamidophenol, the two aromatic protons bearing the OH and NH functional group appeared doublet each instead of singlet. Pls what could be responsible for this?
How do you think AI can be maximized in developing nations? bearing in mind some restrictive factors such as technology growth/
I had prepared 50ml of 0.5M Sulphuric acid and to that I added 20ml of 0.5M sulphuric acid containing 9 drops of 2M sodium hydroxide. I then leached the mixture for 15 minutes using a magnetic stirrer. In the same standard procedure I continued to increase the pH by adding more drops of sodium hydroxide that is from 9 to 34 and 50 drops.
How we can relate Unconfined Compressive Strength of Clay to it's allowable Bearing Capacity?
I have a non linear wiener model (xk = x0 + θ_k*(t_k)^b+ σ B(t_k )). I have a sample of m RMS values collected for m intervals of time.
For getting these parameters (θ_k,b,σ,B(t_k )), can i perform partial differential of PDF and get values?
REF: https://ieeexplore.ieee.org/document/7574329 - Section II.B
Are all historical sources bearing an intellectual character?
Anyone here working or an expert in modeling of journal bearing with surface texture by using CFD ANSYS FLUENT?I have a question to ask related with this topic.Thanks again
If possible , then can the cantilever portion of the masonry buildings will be able to take the load of both partition wall and the slab??? (Soil bearing capacity is high). Suppose, cantilever length is 2 feet on every side and it has to be built on 2nd floor (already the building has been constructed 2 storeyed )
Anyone here working or an expert in modeling of journal bearing with surface texture by using CFD ANSYS FLUENT?I have a question to ask related with this topic.Thanks again
I want to model a rotor. it has 2 bearing to connect to the earth. in the intraction module I set bushes. but i dont khow whats its boundary condition.
Is there any software that helps us in the calculating Safe bearing capacity of the soil, permissible loads on the foundation without actually going the same calculations again and again?
I am trying to generate a faulty acceleration signal with SIMULINK. The inner ring of the bearing is fixed to the shaft. The bearing has 17 rolling elements. I was thinking of creating a fault in the inner ring because it is attached to the shaft. My approach was to add 17 impulses per cycle to the original measured acceleration data in order to generate a faulty signal.
I attached a picture of my Simulink model. What do you think about this approach and is my model correct so far?
10.848 * f_wheel is the Ball Pass frequency of the inner ring.
I am trying to implement an algorithm to detect possible damage at a bearing. In order to test my algorithm, it would be helpful to generate faulty bearing acceleration signals? Does anyone know, if a signal generator (whether in Matlab or Simulink) already exists?
Thank you in advance!
Hello, I am trying to write a program in Matlab to estimate the remaining useful life of a bearing without data of a previous failure. Do you think this is possible? I was thinking to use the amplitude of the ball pass frequency as an indicator but I am not sure how to do so.
Does someone know a paper (or even a Matlab program) which deals with this issue?
I am interested in finding RUL of bearing, which is currently in operation. I could find papers which uses run to failure datasets, which is not of my interest.
Can anyone suggest methods or papers to obtain rul for an incomplete dataset? If I use vibration data, wont it be different for different bearings?
Hi, I am doing CFD analysis of journal and partial arc bearing. And I need to apply the following Reynolds boundary condition ( Pressure Boundary Condition ) by writing UDF.
P=Pa = 0 at Z=0 and Z=1 &
P=Pa = 0 at 0 =< thetha <= 360deg
Cavitation is allowed to occur at ambient pressure by setting all calculated negative pressure equal to zero throughout the iterative solution scheme. This implies that, the lubricant film ruptures and reforms when,
pressure gradient = zero
I am new in writing UDF for Ansys fluent
want to make a fatigue simulation on some mechanical parts like Gears, Bearing, and gear housing. please assume 2 gears in contact.when they Are rotating under constant torque and velocity the stress in every node is unique and varies every time. I can define a signal for a node based on time stress (\Sigma (t)) of the node but I cannot do that for the millions of them. Is there any solution for this problem? I saw some tutorial videos but all of them using one or two signals and applying to all elements but I cannot do that. Stress in posision1 (X1(t),Y1(t),Z1(t)) do not change the same as posision2 (X2(t),Y2(t),Z2(t)). But in tutorial videos stress in po1 is a constant scale of po2 in every time and the scale stays constant. please help me to solve that I have many problems with that.
I am actually wondering what is the range of oxidation potential of alkyl halides, especially species bearing an Iodine atom. I didn't find information in my book (organic electrochemistry by Ole Hammerich & Bernd Speiser). Thank you !
I am currently writing my master thesis in which I am trying to understand the stiffness values of tapered roller bearing. For this, I am have made the model simpler by using only a single segment of the TRB in Abaqus CAE.
During the loading stage, I am able to apply radial loading and find out the radial stiffness of the TRB segment but however, on the application of an axial load, the simulation fails. I am unable to find the problem as to why. Please find attached a picture showing the boundary conditions and the loading definition. The outer ring is constrained on the top and a kinematic coupling is used to constrain the inner surface of the inner raceway with RP2 and a radial load is applied on the same Reference point(RP2).
The load is also constrained in this picture with respect to the global y-axis for radial loads.
I have also tried to do that same by constraining the load in all directions except for the axial direction but the simulation still fails.
The step is set such that NLGEOM is on and the values for time step are 0.01, 1E-015, 1 with a time period of 1.
I have tried many different ways to get axial loading to work but was unsuccessful. It would be of great help to me if any if you could give me some ideas regarding this. Please feel free to ask if you require any further information.
outer race outer dia-130mm
outer race inner dia-106mm
groove radius of outer race 12 mm
inner race outer dia 74 mm
inner race bore dia 50mm
inner race groove radius 12mm
wirth of bearing 30mm
I am trying to make Bearing Capacity Mapping of certain district and points are limited. But i want to cover whole district. If anyone have any idea please explain step by step.
The fulid inside the journal bearing should have minimum amount of thickness so that no metal to metal contact will exist.
Is there any references or books for this ?
can any one provide material on journal bearing .
I want to manufacture the bearing and characterise that
Kindly do needful in this regard
The words acquire, achievement, gain and profit have specific meaning. Acquire and achievement can be used closely bearing the similar meaning. But other two are different. How can we differentiate among them.
Hello every one,
I am doing analysis of Bridge in which elastomeric bearing is modeled as link element between Deck and pier bent. Pier bent portal consist 2 pier and one cap beam on which elastomeric bearing are resting and on elastomeric bearing bridge deck is rest. I am doing non linear time history analysis.
Now (1 )due to elastomeric bearing, moment/forces are not transferred to pier hence bottom moment of pier has not reached Mp value and stresses in pier is very less (at least half of yield stress of Concrete)
(2) Joint Forces at link bottom has reached maximum level of forces and for bearing perfect elastoplastic force displacement curve has given as input of link
(3) Even if pier concrete has not reached at yield stress level CSI Bridge & SAP2000 showing hinges from IO to CP at various time steps.
Why does SAP 2000 Showing hinges in pier even if pier has not undergo plastic moment? Does it is due to yielding of Bearing
As we know, there are so many equations in the direct method to determine the bearing capacity of soils. What is your best suggestion if we had a significant difference in results from those equations? Should we apply a conservative value (minimum) or use the average one? Thank you all.
1:1 mineralogy is easily dispersed under saturated conditions. Is by add organic matter/amendment can stabilize these soil and increase soil bearing
I am trying to do a finite element analysis of rubber bearings. Which FEA software is most suitable for rubber bearings? (ANSYS, LS-DYNA, ABAQUS, MSC Marc)?
I just started extracting DNA from some spiders, using 5-mm ball bearings to grind the specimens in a tissue mill. I had ordered the ball bearings on Amazon, and thought it was a good idea to sterilize them before use, so I soaked them in ~0.3% sodium hypochlorite for 30 minutes. Then I rinsed them with 100% ETOH three times and air dried them. Unfortunately they rusted during the bleaching, so that the bleach was completely brown when I poured it off. Still, I figured it would be all right to use them once (and discard after the first use) because they should at least be free of any DNA.
So I went ahead and used them to grind my specimens, then proceeded with extraction using the Qiagen Puregene Tissue kit. I did cell lysis overnight, roughly 20 hours at 55 degrees. When I removed the samples from the incubator, the lysate was clearly rusty (reddish in color with sediment in the bottom of the tube). At the end of the protocol, the DNA pellets were also quite red. I have done this protocol many times, and the difference in pellet color from the usual whitish/gray-brown was very apparent.
My question is, does anyone know if the rust will cause any harm to the DNA? I plan to use these extractions for metabarcoding, just amplifying short fragments of 400 bp or less. I will run a test PCR, but in the meantime I wondered if anyone else might have experience or knowledge about this particular issue.