I am writing my diploma. I am new to Inventor. There is not enough time, who can help, please help) There is a beam welded from sheets 10 mm thick. The material of the sheets, as well as the welding material, are set using Semantic 2015. Dependencies on the edges, because in these sections, the beam is welded to the longitudinal beams (Figure 1).Loads, then Force applied - 500 N. The result is somehow strange.A 100 mm thick sheet of high-strength steel bent, as shown in Figure 2, 3. Reduced the force to 50 N, the picture is the same.What could be the reason?
Let's go in order. I agree with clause 3 of Article 1358. It clearly follows from this clause that a Utility Model (another's patent) is recognized as used in a product (in your product) if it uses at least one feature from an independent claim of someone else's patent. This only feature used can only be a distinctive feature, since Article 1358 of the Civil Code refers to EVERY feature of an independent claim. "An independent claim must contain the necessary features: - to realize the purpose of the invention (utility model), - to achieve the technical result indicated in the description; The combination of features of an independent claim must provide patentability to the object of the invention or utility model"
It looks like it. element damping is just from combos. Examples are usually associated with either rotor dynamics or FSI analysis using acoustic elements. Or do you shake the containment? Well, there are water tanks))) they can be modeled with acoustic elements. Although it's fleas, of course. g - constant structural damping assign different g to different materials. and why Rayleigh damping is not suitable? well, except that you don't know the right alpha and beta. an approach with the creation of a FE model is used. In the FE model, there can be different objects such as combi14 or simply materials with damping. To assemble the matrix from the FE model is the task of the program. Our task is to assemble the FE model and set up the program correctly. Pushing your objects into its matrices after the program has formulated the matrix is unproductive and does not correspond to the popular approach. A conversation about modal coordinates, apparently, is a conversation about solving by the method of superposition of harmonic or transient analysis. But it is not exactly)
Let's go in order. I think you agree with paragraph 3 of Article 1358. Yes? It clearly follows from this paragraph that if at least one feature from the independent claim is not used, then the patent is not used in the object. Do you agree? This only unused feature can be both a distinctive feature and a restrictive one, since Article 1358 of the Civil Code refers to EVERY feature of an independent claim. That's actually all I wanted to say.
Ratcheting is not stabilization, but the accumulation of deformation from cycle to cycle. but the reverse process is also possible - after all, stabilization and stretching of the hysteresis into a straight line. He even, perhaps, more often. How exactly a particular material will behave under specific conditions is another question. that's it. only in special cases. Let's say we stretch the material. and let us assume that our material is such that at a sufficiently large deformation the Bauschinger effect ceases to be observed. how can it be, for example ... but we have exceeded the yield strength twice. If the Bauschinger effect worked, then during unloading and subsequent compression, the material would begin to plastically deform immediately. And if at the stage of stretching the yield strength was exceeded by a factor of three, then the material would flow in compression without being loaded yet. This leads us to the fact that the yield surface is not rigid, but has the ability to deform in the region of large deformations. But the adherents of isotropic hardening go further. And let's, so that the above crap does not work out, as the fluidity surface shifts, we will also expand it. Then, with a large tension and subsequent unloading and compression, it is possible to choose such parameters in order to fall into a separate particular experiment or several experiments. But, by applying isotropic hardening, we expand the surface not only in one direction, but also in the perpendicular one. If you look at the space of stresses, then let's say tension / compression - it was about sigma1, then perpendicular - sigma 2 or sigma3. And now this is categorically false. That is, for complex loading trajectories, this will not work. Therefore, the combination with isoporny hardening is a dead end. It does not exist in nature, it was simply easier to program it at the dawn of the development of FEM for problems with one-sided plastic deformation and a simple loading path. As a bonus to those who read to the end. There is also combined hardening, by the way, but with good results.
B. Rau
Processes electrochemical processing of metals are used in all industries. With their help, you can perform operations such as drilling, turning, grinding or polishing, milling parts of the most complex configurations, and even remove burrs. In this case, the essence of the processes of electrochemical dimensional processing is the anodic dissolution of the metal during electrolysis with the regular removal of the resulting waste. And therefore - and this is the most valuable - for the processes of electrochemical "cutting" there are practically no hard-to-cut metals.
Everything these advantages of electrochemical processing processes can be successfully used at home for many interesting and useful jobs. For example, with their help, it is possible to cut an elastic plate from a razor blade in 20-30 minutes, cut a hole of complex shape in a thin sheet of metal, carve a spiral groove on a round rod. To perform all these works, it is enough to have an AC rectifier that gives an output voltage of 6-10 volts, or a rectifier for micromotors of 6 volts, or, finally, a set of 2-3 batteries for a flashlight. Pieces of wire, metal, glue and other auxiliary materials can be found in any home workshop.
Milling.
If in some blank you need to make a deepening of a complex configuration - for example, cut out the apartment number - then for this you need to take a sheet of drawing paper and draw on it a life-size contour of the deepening that you want to get. Then, with a razor blade or scissors, cut and remove the drawn outline, and cut the sheet in accordance with the shape and size of the workpiece. Glue the mask template (1) obtained in this way with rubber glue or BF-88 glue onto the surface of the workpiece (2), attach the wire from the positive pole of the rectifier or a set of batteries to the workpiece and apply 1-2 layers to all its surfaces remaining without insulation any varnish or nitro paint. It's a good idea to varnish or paint the mask template itself. After allowing the coating to dry, lower the workpiece into a glass with a concentrated solution of common salt, place a cathode plate (3) of any metal opposite the mask template and connect it to the negative pole of the rectifier or current source.
How as soon as the current is turned on, the process of electrochemical dissolution of the metal inside the contour of the mask template will begin. But after some time, the intensity of the process will decrease, which can be seen from the decrease in the number of bubbles released on the cathode (3). This means that an insulating layer of process waste has formed on the treated surface. To remove them and at the same time measure the depth of the recess, the part must be removed from the glass and, trying not to damage the mask template, clean off the loose layer of waste from the surface to be treated with a small hard brush. After that, periodically removing the part to control the dimensions and remove waste, the process can be continued until the depth of the recess reaches the required value. And when the processing is completed, having removed the insulation and mask template, the part must be washed with water and lubricated with oil to prevent corrosion.
Stamping and engraving.
When in a thin sheet of metal it is necessary to make a hole of complex configuration, the principles of electrochemical processing remain the same as in milling. The only subtlety is that in order for the edges of the hole to be even, the mask template (1) must be glued onto the workpiece from both sides. To do this, the contours of the mask template (1) should be cut out in a sheet of paper folded in half and, sticking the template on the workpiece (2), orient it along one of its sides. And besides, in order to speed up processing and ensure uniform removal of metal from both sides, it is advisable to bend the cathode plate (3) in the form of the letter "U" and place the workpiece to be processed into it.
For the manufacture of sheet steel - for example, from the blade of a razor blade - parts of any profile act somewhat differently. The profile of the part itself is cut out of paper (1) and glued to the workpiece (2). Then the entire opposite side of the steel sheet is varnished, and on the side of the template, varnish insulation is applied so that it does not adjoin the template. And only in one place the applied insulation needs to be brought to the template with a narrow jumper (3) - otherwise the dissolution of uninsulated surfaces around the template may end before the contour of the part is formed. To obtain more accurate details, two templates can be cut out, glued to the workpiece on both sides and processed in a U-shaped cathode. In similar ways, you can make various inscriptions on metal, both convex and "depressed".
Threading and spiral grooves.
One A variation of the milling process is electrochemical spiral grooving and threading. This method can be useful for making at home, for example, wood screws or twist drills. When cutting a thread on a screw, as a mask template (1), you need to take a thin rubber cord of square section 1x1 mm, wind it in a spiral on a cylindrical workpiece (2) with tension and fasten its ends with threads (3). And then those surfaces of the workpiece that are not subject to etching, isolate with varnish. As a result of electrochemical processing, a spiral thread cavity is formed on the workpiece between the turns of rubber. Now you need to sharpen or, more precisely, make that end of the workpiece conical, which will serve as the sting of the screw entering the tree. To do this, the workpiece must be removed from the bath, remove the rubber from it and dry it. And then, varnishing its surface in such a way that only the first 2-3 threads of the thread remain open, the workpiece is returned to the bath and the electrochemical treatment is continued for some more time.
For for making a twist drill at home, as a mask template (1), you need to take three rubber cords of the same section and wind them onto a heat-treated cylindrical workpiece (2), but already in two passes. Then, the surfaces of the workpiece that are not subject to processing, and for reliability, the rubber cords must also be varnished and, lowering the part into a glass-bath, electrochemical milling of the drill grooves to the desired depth should be carried out. Now these grooves need to be widened to form the so-called "back" of the drill (3). To do this, two out of three cords are removed from each strip of rubber insulation, and electrochemical milling continues for some more time. After that, removing the remaining insulation and sharpening the lead, you will get an excellent twist drill.
Grinding.
To to grind the surface of cylindrical parts by electrochemistry, in addition to traditional equipment, you must have a small electric motor or drill. After pre-isolating with varnish the surfaces of the part that cannot be processed, fix it on the motor shaft (1), install the engine vertically on some bracket and lower the end of the part to be machined (2) into the bath with electrolyte. In this case, it is best to organize the power supply of the anode part (2) with a sliding contact going to the motor shaft, and make the cathode (3) flat, equal in length to the treated surface. Now it remains to turn on the electric motor and power the bath. With the beginning of the process, the darkening of the surface will begin - the formation of waste. To obtain the correct cylindrical shape of the treated surface, these wastes must be continuously removed. It is convenient to do this with a toothbrush with a bristle shortened for rigidity, which, pressed against the part, should be moved up and down measuredly. By periodically removing the part to measure the diameter, in this way it is possible to obtain a surface with dimensional accuracy according to the second class.
Polishing.
For In order to polish any steel surface, prepare two wooden "kolobashki" (1) measuring 40x40 millimeters: one for rough and the second for fine polishing. Fix on them the angled tin plates (2) acting as a cathode so that their position can be adjusted in height. To debug the polishing process, you need to take a workpiece (3), connect it to the positive pole of the current source and place it in a bath with electrolyte so that the level of the solution lies slightly above the horizontal part of the cathode (2). Then the rough "kolobashka" should be dipped with one of the ends into the salt solution in the bath, removed and poured on it with a pinch of fine abrasive powder. Now, turning on the current, start polishing the part in a circular motion. In this case, it may happen that the electrochemical dissolution will be faster than the process of removing waste by the abrasive. To eliminate this discrepancy, raise the cathode plate higher and the dissolution rate will decrease. After polishing the entire surface with the first “bowl”, change the electrolyte solution to a clean one, wash the part from the abrasive and use the second “bowl” to start fine polishing, which should be carried out either without abrasive at all, or using tooth powder instead. With some training in this way, you can get a mirror surface on parts two to three times faster than mechanical polishing.
"Frost" on white plate.
Take empty tin can or just a piece of tinplate and connect to the wire from the positive pole of the rectifier. And connect any metal rod to the other pole, having previously made a cotton swab at its lower end. If now this kind of "shaving brush" is dipped into a solution of common salt and then slowly driven over the surface of the tin, then amazing things will happen to it. In those places where you brushed 2-3 times, sparkling crystals of "frost" appear - the crystalline structure of the tin coating will come to light. If you continue the process, then gray islands of waste will soon appear on the metal, firmly associated with the metal. And in the future, the entire surface of the tin will become spotty gray, with a characteristic bizarre pattern.
For To obtain various decorative patterns on metal, you can try using solutions of different salts or acids. So, for example, if instead of a solution of common salt we take a one percent solution of sulfuric acid, then the "appearing" crystals will acquire a brown tint. If a tin plate is sprinkled with toothpowder, then the “frost” pattern will become more contrasting, with a milky gray tint. By preheating individual parts of the tin piece until the tin melts locally and quickly cooling them in water, one can obtain the most intricate ornaments on metal. Such ornaments look especially good if they are covered with colored varnish on top. Try it and you will see that a lot of beautiful things can be made from a simple tin can.
I read about such an interesting processing method. I want to implement it on a CNC machine :)
From the book "Handbook of a process engineer in mechanical engineering" (Babichev A.P.):
Electrochemical dimensional processing is based on the phenomenon of anodic (electrochemical) dissolution of metal when current passes through an electrolyte supplied under pressure into the gap between the electrodes without direct contact between the tool and the workpiece. Therefore, another name for this method is anodic chemical treatment.
The tool electrode is the cathode during processing, and the workpiece is the anode. The electrode-tool will move progressively at a speed Vn. The electrolyte is fed into the interelectrode gap. The intensive movement of the electrolyte ensures a stable and high-performance course of the anodic dissolution process, the removal of dissolution products from the working gap and the removal of heat that occurs during processing. As the metal is removed from the workpiece-anode, the tool-cathode is fed.
The rate of anodic dissolution and processing accuracy are the higher, the smaller the interelectrode gap. However, with a decrease in the gap, the process of its regulation becomes more complicated, the resistance to electrolyte pumping increases, and breakdown may occur, causing damage to the treated surface. Due to the increase in gas filling at small gaps, the rate of anodic dissolution decreases. Should choose
gap size that achieves optimum metal removal rate and shaping accuracy.
To obtain high technological indicators of ECM, it is necessary that electrolytes meet the following requirements: complete or partial elimination of side reactions that reduce the current efficiency anodic dissolution of the workpiece metal only in the processing zone, excluding dissolution of untreated surfaces, i. the presence of high localizing properties, ensuring the flow of electric current of the calculated value in all areas of the treated surface of the workpiece.
The most common electrolytes are neutral solutions of inorganic chloride salts, nitrates and sulfates of sodium and potassium. These salts are cheap and harmless to service personnel. An aqueous solution of sodium chloride (table salt) NaCl has been widely used because of its low cost and long-term performance, which is ensured by the continuous reduction of sodium chloride in the solution.
Installations for ECHO must have filters for electrolyte purification.
The roundness of the hole achieved by itself pleases. But the funnel shape is not encouraging.
I will now try to pump the electrolyte through a medical needle.
Modified April 18, 2008 by destiK.: Technika, 1989. - 191 p.
ISBN 5-335-00257-3
Download(direct link) :
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In electrochemical milling, a coating of any acid-resistant paint applied by a stencil can serve as a protective coating. The pickling solution in this case consists of 150 g/l sodium chloride and 150 g/l nitric acid. Etching occurs at the anode at a current density of 100–150 A/dm2. Copper plates are used as the cathode. After the termination of the process, the cathodes are removed from the bath.
Electrochemical milling is more accurate than chemical milling.
PRE-TREATMENT OF ALUMINUM AND ITS ALLOYS
To ensure strong adhesion of the electrolytic coating to aluminum, an intermediate layer of zinc, iron or nickel is applied to the surface of the latter (Table 21).
CHEMICAL AND ELECTROCHEMICAL POLISHING
A smooth metal surface can be obtained by chemical or electrochemical (anodic) polishing (Tables 22, 23). The use of these processes makes it possible to replace mechanical polishing.
When aluminum is oxidized, mechanical polishing is not enough to achieve a shiny surface; after it, chemical polishing is necessary.
21. Solutions for aluminum pretreatment
Orthophosphoric acid Glacial acetic Orthophosphoric acid
280-290 15-30 1-6
Acid Orange * For:
dye 2
pinned surface
1st intermediate processing
ratu-ra. WITH
4. orthophosphorus!
Triethane! lamin
500-IfXX) 250-550 30-80
Triethanolamine Catalin BPV
850-900 100-150
Orthophs ph rthic acids Chromic thydrnd
* Products ps mining are processed by flushing in the same mine 6A / dm2
trochemical polishing When polishing precious metals by chemical or electrochemical methods, their losses are completely eliminated. Electrochemical and chemical polishing can be not only a preparatory operation before applying electroplating, but also the final stage of the technological process. It is most widely used for aluminum. Electrochemical polishing is more economical than<ими-ческое.
The current density and duration of the electropolishing process are selected depending on the shape, size and material of the products.
COATING PROCESS TECHNOLOGY
SELECTION OF ELECTROLYTES AND PROCESSING MODES
The quality of the metal coating is characterized by the structure of the precipitate, its thickness and uniformity of distribution on the surface of the product. The structure of the precipitate is influenced by the composition and pH of the solution, the hydrogen released together with the metal, the electrolysis mode - dark
polishing
M41
with SS
Density
„|§..
cathodes
From sent
carbonaceous
I-IL
15-18
1,63-1,72
12XI8H9T, over
1-5
10-100
From steel 12X18H97
H:rusty1d
From styles 12X18H9T Aluminum and 3-5 20-50 - (aluminum) stainless
0.5-5.0 20-50 1.60-1.61 From copper or evine Copper
temperature, density of the goka, the presence of swing, filtration and 1. d.
To improve the structure of the precipitate, various organic additives (glue, gelatin, saccharin, etc.) are introduced into electrolytes, complex salts are precipitated from solutions, the temperature is increased, continuous filtration is used, etc. The released hydrogen can be absorbed by the precipitate, contributing to an increase in brittleness and porosity. , and the appearance of so-called pitting points. To reduce the effect of hydrogen on the quality of the precipitate, the parts are shaken during the process, oxidizing agents are introduced, the temperature is increased, etc. The porosity of the precipitate decreases with increasing thickness.
The uniform distribution of the precipitate on the surface and delirium depends on the scattering ability of the electrolyte. Alkaline and cyanide electrolytes have the best scattering ability, acidic electrolytes are much less, and chromium electrolytes are the worst.
When choosing an electrolyte, it is necessary to take into account the configuration of the products and the requirements that apply to them. For example, when coating products of a simple shape, you can work with simple in composition electr>-
lantamn that do not require heating, ventilation, filtration; when coating products of complex shape, solutions of complex metal salts should be used; for coating internal and hard-to-reach surfaces - internal and additional anodes, filtration, mixing; to obtain a brilliant coating - electrolytes with complex brightening and leveling additives, etc.
GENERAL SCHEME OF THE TECHNOLOGICAL PROCESS
The coating process consists of a series of sequential operations - preparatory, coating and final processing. Preparatory operations include machining [parts, degreasing in organic solvents, chemical or electrochemical degreasing, etching and polishing. The final processing of coatings includes dehydration, clarification, passivation, impregnation, polishing, brushing. After each operation