MECHANICAL DESIGN TOOLS

Static Vs Dynamic Finite Element Analysis

A simulation called dynamic when some of parameter are variably in line with time alteration or can be said time based simulation. For example box positions in <a href="http://fajaryannu.blogspot.com/2009/06/dynamic-system-simulation.html">dynamic motion simulation</a> post, are categorized as time based simulation because its change collateral with time increases. If your simulation are contains displacement, velocity, acceleration or any variable that depend on time so it’s your dynamic simulation. How about Finite Element Analysis, what kind of FEA simulation are categories as dynamic? For example in Stress simulations post, are categorized as static FEA since no time based variable are involve, how about the video that obviously shows stress vary with time? No, its only animation with using load factor and there are no stress output data generated by Msc.Visual Nastran 4D that depend of time. The main distinction parameters to grouping our analysis in static or dynamic field are equivalent stress with von misses theory (svm): <div class="fullpost"> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgdK4vTidvMSNOQzdZ1HFyBX0V5QpOEreR41XfcKf4csOBPBSpJ8xASPW-Y03Ia7IldPaCI1MhQbUGYeXGmt-jUdIDkvUGKNV02zPPmvY9CqAiA1fwjx7LmzHMMKgU6xyfIc6GQFA-puBs/s1600-h/clip_image004%5B8%5D.gif"><img alt="clip_image004" border="0" fix="fixed" height="45" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgg2H-kMEOgPSr8_pLYUzeBbN0XDZvcm9LyPGV5d8l0TiXicbP0RMHz2hMUlRMk5rpFdJM32M2uPJpS6hhbqZ7foZzZNMRPcaTtRyNJt5v7uachlM-UslfjPqZYyGHyOpMKnzNMQiznSug/?imgmax=800" style="border-width: 0px; display: inline;" title="clip_image004" width="372" /></a> Remark: <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg8O7SlV5353S1J0FJ0dZz1LTfIBr5RouheHdAGaf01x6n_iqxopowfRnCTVKp90PwTgTISvT-WD9VFLXDy8QC_qPJuhDNIrp6t1xB6k0khg49FvAYg16AJ_yMDTDMM1xSVMWngQ0D5CpI/?imgmax=800"><img alt="clip_image006" border="0" fix="fixed" height="72" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgPsZLROWBAzcDxYMrLP15ZJ3IqtrgWsp1Nmh0WsIOzAIF8zkm2uNe2m_aJQQEqKSwm50v9T3tpt7kF_1v9uMxx9PutzNN8Wqyw06YPxGa8EZRorWzUWQlZFi7GvHCylKbiw4z4hGWuzCk/?imgmax=800" style="border-width: 0px; display: inline;" title="clip_image006" width="175" /></a> To gain comprehension and knows the different more clearly to identify a Finite Element Analysis category, I will explain each below: STATIC FEA Finite Element Analysis described as static if meet the condition where yield strength of material are greater than generated stress (svm≤syield), as an effect for exposing external load in object or model. So if we said our visual display consist of frame by frame in proportion with time, any deformation or shape transformation as calculation result that performed previous frame are neglected in the next frame so our model assume recover instantly or never been receive any load before, this assumption are applied because stress works in elastic area of material or usually known as small deformation analysis. This static FEA regularly used to verify whether current design meet infinite life time work condition or not ,of course combining the stress calculation result with theory of failure that include safety factor in it. DYNAMIC FEA In contrary, if generated stresses from external load are passing yield strength so your simulations are categorized as dynamic FEA (svm>syield). Deformation or change shape in analyzed model because of exposed load aren’t neglected so continuously effect especially shape transformation are considerate as calculation variable for next frame depend on time range that decided by user, its known also as Large deformation analysis These methods are useful to see behavior of our model when work in over load condition, such as collision analysis, crack propagation and etc. In picture below I made some example a loaded bar tip and hold fix in the other end with frame by frame overview <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEivX-90MtU7sq6Tt2Od_ZuPksjCGdkWV4CxPrJ-OYwTmApRzvy-9f0HFCAwi0EPja3ZhrTPI9TGA4sYpSSo3xcwZEpZf4YDqnU_jMd33Oc6_bMTB7vqtnS7HDIVFD3gx2wubkrSvdAdbiQ/s1600-h/clip_image012%5B7%5D.jpg"><img alt="clip_image012" border="0" fix="fixed" height="144" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh2hp1WXyKXpRAhTUVoOJeO_5diEVvH4XUsKt2FR9at096dzhNfr6ik25cXFyezLDud4cZdXrpDoTw87q7UOgavvBom0urjb8DtLVKrnKtvPUem9xdqZ4PU-dgeuXAgOMqRdL4p5I-tw54/?imgmax=800" style="border-width: 0px; display: block; float: none; margin-left: auto; margin-right: auto;" title="clip_image012" width="373" /></a> To decide whether our FEA are static or dynamic can be easily recognize by using Stress-Strain Diagram, in which area they perform analysis <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjqrvYijhNrzA0cikKLe6o6jykwasVzDVvIFcZiw1h7f0C_cpx-cR3x3Imj7wLO1mnkpzNVtXH4VRmbXwgKKnVYACOCGLvmlMPxUDfo7UOhvPt9WJWo5Ae2HLZ1eC3ryF4AGWkrsH7pXaU/s1600-h/clip_image014%5B5%5D.jpg"><img alt="clip_image014" border="0" fix="fixed" height="304" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrt0Gvnd7yYKf1Q1ezEltgh3uESCN6EtwSb75_iksWJRNGKiusK-u8v6GxQJRu8uAaRfotnHC_3_XKnHZtna9JozwwBN3cBLstvpVYF7vV8U83D7-2HU4tcQvwU7LSIyj5dQEkotJWA-E/?imgmax=800" style="border-width: 0px; display: block; float: none; margin-left: auto; margin-right: auto;" title="clip_image014" width="297" /></a> In some mechanical engineer literature, "Static FEA" also mention as "Linear Static FEA" since linear slope in elastic area base on above diagram. In Vn4D we can collaborated both Motion and Finite Element Analysis in a single simulation environment of course with condition that calculated FEA have to meet linear static FEA requirement, if doesn’t, it will shows error message that says the calculated result doesn’t pass the validation test. <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhHjg2adRBvdXSmyscI25feq90LEvNHgEN1dzDrMct8oY-2RQ0v3lecvns4KbRnv-4mUwgun1JQKVTpG1LlW1z7Lx25Frgzqat4XplCDpc33lISX9bNho_yEpGmTQl9nzMLK_0GrDbbtI4/s1600-h/clip_image015%5B6%5D.jpg"><img alt="clip_image015" border="0" fix="fixed" height="94" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi9rl7-ZcX2nlcJzfKjClVV4y7Vw0s9KRLbo307Srk3VN3KB_1LZrfg5hjBjKO9XNzekUXyLFLcu1cH-aXy-eMVU_iiZiXh0a6SL6tpzjKcGErw_V6YzAbgyNLJWnMfBYPP6FWnaq34Hpk/?imgmax=800" style="border-width: 0px; display: block; float: none; margin-left: auto; margin-right: auto;" title="clip_image015" width="376" /></a> Now we know that Finite Element Analysis also divides in two categories, If linear static FEA can be handled by Msc.Visual Nastran 4D (Vn4D) so how about dynamic FEA? I will explain how to perform Dynamic FEA with software ANSYS-LS DYNA in other post. </div>

Static Vs Dynamic Finite Element Analysis

A simulation called dynamic when some of parameter are variably in line with time alteration or can be said time based simulation. For example box positions in dynamic motion simulation post, are cate…

21 Jun 2009

Stress Simulation

This page will explain what kind of Stress simulation with Finite Element Analysis (FEA) in Msc.Visual Nastran 4D (Vn4D). The main idea in FEA are simplifying continues model become discrete that build by element and node, so simple isn’t it?? Converting continues 3D model to become discrete element are determine accuracy of the result that will be generated, so user experience and knowledge in FEA will be the main issue, big element size resulting coarse result but small element size will resulting unnecessary effort that affect in increasing computational time and hardware work load so focus on our analysis goal are the golden mean, feature in Vn4D called “Control Mesh” are the answer, where we can smoothing element size in local places which are become our analysis objective. <div class="fullpost" style="font-family:times new roman;"> First we have to know what an element that generated by our software, not like CAM Software that are specializing in Finite Element Analysis such as ANSYS, there are no other option for deciding what kind of an element that use in FEA, Vn4D only using “Ten-Node Quadratic Tetrahedron” about advantage or disadvantage and why this type of element are choose by Vn4D will be discus in different post, but keep in mind that I‘m not going to guide you step by step how to perform stress simulation using Vn4D just what we get and how to achieve better result with feature in this software. For an example I will use two different model that expose by equal force in different direction at both end, they are notched bar and hole plate which is already transform in element and node: 1. Coarse model with constant overall element size <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjpSavighnJ1g7F58Ctod_LDw7VNfUUU1LWl4Al05U9mZ5laCG71Cgma2KhtkiodofG_FpgFXzpd0OFAdBu-Ot-AmkCmykY2G-YDLhN-oFHy_D_7KixiqfU6L2NiR9g9NV1o3t-86o_CQ8/s1600-h/clip_image001411.jpg"><img alt="clip_image001[4]" border="0" fix="fixed" height="195" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjcu0Gog_yhkdD4_hD5-a3l1EMMhitz9NpfNRnIub75fmabPi_NpZcZWaO5ZabW-nLCayjtJSQLf_sqpcaaRwRA42DJyW_SDag9dE0_4Ob1K8pUqKfCZuqXXPIR_wlqcVgpaypUvTRoVZ4/?imgmax=800" style="border-width: 0px; display: block; float: none; margin-left: auto; margin-right: auto;" title="clip_image001[4]" width="244" /></a> As you see in the picture above, our 3D model become coarse especially rounded shape 2. Smoothing model with application “Control Mesh” in area that identify exposed by large stress concentration <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjfefbdXLz9mitKzS092f8gjjkmOdWAG4B2cgC76JRj4qRyt3a7HqstV_ED_RSfO1eQ9oNfIDkZx0OyztdPUbZLe-Sk4bRhhj3aDpzEXMdFlR4UVFfiV_WlNB4Zjt2EQFvggS4hX82LvII/s1600-h/clip_image00242.jpg"><img alt="clip_image002[4]" border="0" fix="fixed" height="205" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjeUZc2UBjB5m9nerX5eoUNNiGEsDecr_Nj0twYQXJ0-zd1uC4vLmRfPJH0yx4uZ1xxaVIVoLUA_equCZ7GeZ29C6Sm18mI3x2RYLVFShdz2N5aRZct_CBEV6U1F9KBX3U8dBWppsQZp2k/?imgmax=800" style="border-width: 0px; display: block; float: none; margin-left: auto; margin-right: auto;" title="clip_image002[4]" width="244" /></a> Improvement in the critical shape area will reduce generated max error 3. Smoothing model with reducing overall element size a half from model no.1 <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgsKtHpWjqMTPmvummbOFTPX8nJVtOI6LKvCHaL4nxt1g_9h8h2cgDRJab6xUJ1oz2_1XwNV4f5fh-asOigmvzZKUg3yki8pAe4wb9nHvBhyphenhyphendf9E3YRyy1bGZQpiz5iGtvKjFlhmII0HSg/s1600-h/clip_image00442.jpg"><img alt="clip_image004[4]" border="0" fix="fixed" height="197" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiNifHWO4BXq6G1aH4aTZ962O6KDYskmP9lxcyHoqqLcG1gxaWXnzOto2ZutkSRQOnG1T2t1jndua4nfT_eqFCmPIaJEyDU1woGd52oKHyiTxLS_NamHSxqwSLYsFYJiIpZj2u3DPTMmQc/?imgmax=800" style="border-width: 0px; display: block; float: none; margin-left: auto; margin-right: auto;" title="clip_image004[4]" width="244" /></a> Smoothing element size by a half contribute slightly reducing max error, continuing by reduce element size will perform better result but in contrary will increase number of element and node. For better overview about an effect of mesh size can be seen in table below: <table border="1" cellpadding="2" cellspacing="0" width="400"><tbody><tr><td valign="top" width="108">Model Shape</td><td valign="top" width="136"> Notched bar </td><td valign="top" width="141"> Hole plate </td></tr></tbody></table> <table border="1" cellpadding="2" cellspacing="0" width="400"><tbody><tr><td valign="top" width="126">Sample No</td><td valign="top" width="40"> Model 1 </td><td valign="top" width="49"> Model 2 </td><td valign="top" width="44"> Model 3 </td><td valign="top" width="45"> Model 1 </td><td valign="top" width="53"> Model 2 </td><td valign="top" width="42"> Model 3 </td></tr><tr><td valign="top" width="126"> Mesh size </td><td valign="top" width="40"> 10 mm </td><td valign="top" width="49"> 10 mm </td><td valign="top" width="44"> 5 mm </td><td valign="top" width="45"> 10 mm </td><td valign="top" width="53"> 10 mm </td><td valign="top" width="42"> 5 mm </td></tr><tr><td valign="top" width="126"> Control mesh size </td><td valign="top" width="40"> - </td><td valign="top" width="49"> 2 mm </td><td valign="top" width="44"> - </td><td valign="top" width="45"> - </td><td valign="top" width="53"> 2 mm </td><td valign="top" width="42"> - </td></tr><tr><td valign="top" width="126"> Node </td><td valign="top" width="40"> 581 </td><td valign="top" width="49"> 1555 </td><td valign="top" width="44"> 2818 </td><td valign="top" width="45"> 1051 </td><td valign="top" width="53"> 4979 </td><td valign="top" width="42"> 5828 </td></tr><tr><td valign="top" width="126"> Element </td><td valign="top" width="40"> 276 </td><td valign="top" width="49"> 835 </td><td valign="top" width="44"> 1538 </td><td valign="top" width="45"> 495 </td><td valign="top" width="53"> 2803 </td><td valign="top" width="42"> 3229 </td></tr><tr><td valign="top" width="126"> Max error </td><td valign="top" width="40"> 12.2% </td><td valign="top" width="49"> 6.74% </td><td valign="top" width="44"> 8.9% </td><td valign="top" width="45"> 7.2% </td><td valign="top" width="53"> 1.3% </td><td valign="top" width="42"> 3.3% </td></tr></tbody></table> From table above we know that using “Control Mesh” feature will give significant error reduction with additional node and element that still tolerable to achieve analysis goals, but if your supported hardware are able to perform large computational process maybe I suggest to reduce overall element size since smaller element size means getting toward to continues model as our original object for stress simulation, so back again its up to you what kind of constraint do you have?<object height="344" width="425"><param name="movie" value="http://www.youtube.com/v/KDpKwQYfZPc&hl=en&fs=1"><param name="allowFullScreen" value="true"><param name="allowscriptaccess" value="always"><embed src="http://www.youtube.com/v/KDpKwQYfZPc&hl=en&fs=1" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object></div>

Stress Simulation

This page will explain what kind of Stress simulation with Finite Element Analysis (FEA) in Msc.Visual Nastran 4D (Vn4D). The main idea in FEA are simplifying continues model become discrete that bu…

15 Jun 2009

Basic Simulation

Main idea of simulation are bringing phenomenon in the real life condition to numerical approach which is applying ideal condition with visual display or just numeric calculation. As the methods are approximation so there are some error that produced but with an experience and supported by correct device, we can minimize an error itself so practice are the best teacher. With explanation above can be assumed that we are playing with prediction here, whether its giving good result or totally fail depend on how much our knowledge about the project. I'm going to share what I know to give you simple guidance especially for newbie how to perform a simulation, for better understanding please read first posting about Dynamic System Simulation because I’ll made some correlation example in that post. Whats needed to perform a simulation, all example are related with <a href="http://fajaryannu.blogspot.com/2009/06/dynamic-system-simulation.html">Dynamic System Simulation</a> post: 1. Goals Before doing anything lets set our goal first, so we can see our path and what tools are needed Example: Make some mechanism that transfer an object following a path in continues cycle 2. Tools What device or tools that will be correct to supporting our project, hardware or even software as we know there are many of both which is build with special purpose, from this we can measure the complexity level of our simulation. 3. Model Now prepare the model, create as simple as you can but still keeping our goal for this simulation if involved models are complex divide it in to groups that have certain function, this is for preventing missing component when setting up complex model because some simulation software doesn't have 3D builder feature even available its just additional with minimal feature so for complex model can achieve by exporting from CAD software, now the questions "Are simulation software has a feature to update models from CAD software?" if you use Vn4D there are a feature that support this by using "Tools - Update from CAD" Example: My models are divide in to three category base on its function Dropper, Convey, Lifter which is consist of bodies or other sub-categories. <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhPoXTXcvwgeJWyyFJ409tnWmRdgftjokCJfJwvKH9SDorm99AXgeJ06DcWWQrPaO-zHqxN_x7cvaQgwRznVE4WlZjb65e6kSu40fQUNxdCt9iHvDou4jeb_2J9IOsudu6Xms9_0cCc350/s1600-h/clip_image002%5B24%5D.jpg"><img alt="clip_image002" border="0" fix="fixed" height="163" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiWlEGmnQyg7riMobxT407ujQ2qFNG51ubtYoVLwlT1_N1w9MOtPPmLpKX64Chh8IXlJ4Zs-FnrVo7OyyTOEkIJ_YYczGiRawH20W8VkEPdBsqh4liATjc7J0FCBXVOqO8OGxqRX414tHM/?imgmax=800" style="border-width: 0px; display: block; float: none; margin-left: auto; margin-right: auto;" title="clip_image002" width="403" /></a> 4. Boundaries This stage require user skills to transfer their knowledge become virtual environment in simulation software, what kind of limitation of our bodies so if they are combined become a mechanism that represent our goals, visual display parameter and inputting mechanical parameter become part of this also. 5. Setting analysis After adjusting virtual environment, then advance to setting up kind of analysis that become our output, we can choose in Vn4D whether dynamic, Finite Element Analysis (FEA) or both combined. Don't forget to choose correct numerical approach in order to minimize an error become very important item. 6. Reading result The last one is reading result, since there are many computational data that produce by our software whether readable or not, simplify it by taking or monitoring necessary data only to reduce processing time but still have direction in achieving purpose of our simulation, the important thing don't forget to verify an error that produced, it's determine whether our simulation can be answerable with appropriate result or just playing around with coarse result, if your data result still giving large an error, you can go back to check what missing item in each stage, try to avoid this because you have to work twice so like I said before experience, knowledge and carefulness from user are the main important thing. To make it simple read this flowchart <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhoaT2osjp-eBGZsQYVhiiKulNw83nxPjpQXtfzi0hH9moSwI1p7e8Buvk4e9a6N6T6iNsI6wjmcHbJM5nayHQMnZiH_jaq3uDz-bZrzApCF7XEpQJ-rmct-I3NyEd8PCtJSTc1q1R5Ei0/s1600-h/clip_image004%5B5%5D.jpg"><img alt="clip_image004" border="0" fix="fixed" height="204" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh_hOFu0_NSkrhoQ7AcoqW_vWv-MrrDX6t55o_jVRSA0E2pV_jVlwqFacwo3x_P2AYKKR_sxy9zjB5x5aijvi-kCMzzWgG4NG015W-HAGVR-KVFK2VmXy1L7ttI5p-i7CFqtKgN2oBEuNs/?imgmax=800" style="border-width: 0px; display: block; float: none; margin-left: auto; margin-right: auto;" title="clip_image004" width="404" /></a> Simulation are very become important stage before applying new design invention since trial and error become old fashion method with high cost for prototyping, so if we can do half in virtual environment, why not???

Basic Simulation

Main idea of simulation are bringing phenomenon in the real life condition to numerical approach which is applying ideal condition with visual display or just numeric calculation. As the methods are a…

07 Jun 2009

Dynamic Motion Simulation

By continuing my first posting about introduction Vn4D in Indonesian language, now I'll make some simple application for this software to perform dynamic simulation, this is an example for multi-body simulation and I made in a bit complex system but with simplealgorithm. I'm only explaining the algorithm not the syntax so you can apply with other software. Let's get straight to the point, first of all before starting simulation we need a model, see picture below: <img alt="" border="0" fix="fixed" id="BLOGGER_PHOTO_ID_5344526318412486706" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjOd_lCtVguAu7UkMdQx16cHLD9g_3xjgeTomvh9J3r6BuX6Aox6BdJTTpCG0KTOpgxYU9cpTXwDsrn8IrhKdTQp8K1zM_jY3ZH7sp1sTrgXqtAJ9seJ-Oq0H6y4qGfGZB18hvi2F7xYXc/s400/Model.JPG" style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 400px; height: 219px;" /><div class="fullpost">I divide in to three part mechanism:1. Dropper : This mechanism transferring box from top to bottom conveyor, consist of spade and sphere as weighter 2. Convey : Moving object in horizontal direction or transferring box from dropper to lifter and contrary 3. Lifter : More complex mechanism that transferring box from bottom to top conveyor, divide again in two component (mover and riser) with detailed each in the picture above.Next step are planning how our mechanism work, see diagram below for overview.<img alt="" border="0" fix="fixed" id="BLOGGER_PHOTO_ID_5344526677390494402" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgwRQ8NwYIfZhZf8p8pbT9W7i5gRrohhrpGBXbls5YmgqphFMJhxcfcvDScFEhp1sLh6v_PFDY2mP5ajxhtpqStjWPQzHUv4oI0_rGJidj6BfJpPL06kLmn9qkVdB0tmwiZM9hJnnK7dpE/s400/Diagram.JPG" style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 400px; height: 134px;" />How to make our simulation run with following diagram above, I'll make it simple by using question-answer method for better understanding.Q: How to make the box move via bottom conveyor to the lifter? A: Set conveyor surface velocity to "n" mm/s and don't forget to set collide behavior between box and conveyor, remember to set collide on a pair of body that really means to be touching each other in simulation Q: What triggering lifter starts to work? A: lifter work when the box fully leaving conveyor, first we have to know weight of conveyor and box independently then read constraint force if only measure weight of conveyor its mean box already leaving the conveyor surface and combine with other parameter to indicate when lifter work for lifting or reset to its original position, such as readable constraint force at the top conveyor. Q: I see the mini lifter and the raiser move at the same time with different slot distance, how to make this happen? A: it’s just simple, we know the distance now the speed for each found by comparing V1/d1=V2/d2, since they travel at the same time, you'll find V1 and V2 value. Q: How does the actuator works? A: Of course readable parameter of distance become indicator, no matter mini lifter or raiser as the reading object they reach the top at the same time, then actuator will pushing pad until fully stroke Q: How does the motor works? A: Motor work when actuator are fully stretched, then rotate with certain angular velocity until desired angle position achieve and back to reset position when constraint force of top conveyor read sum of weight box and conveyor itself. Q: Are setting parameter for top conveyor same with bottom conveyor? A: Yes it does, just velocity direction need to set an opposite. Q: How to make Dropper work by using its natural movement? A: Now this is need a calculation out side from software since there aren't control except limiting hinge movement by degree, first we have to now length of arm between hinge with sphere (l1), weight of sphere (F1) then length of arm from hinge to spade center gravity (l2) and spade weight (F2), of course weight of box (Wb) as known variable, then make sure current condition are meet with this equation F1*L1<(F2+Wb)*L2, if doesn't you can edit sphere weight without changing dimension shape.Clips below are generated output from Vn4D, I also give a graph to monitor what torque motor that needed to lift the raiser component with constant velocity <object height="344" width="425"><param name="movie" value="http://www.youtube.com/v/uJJfCzKbKjA&hl=en&fs=1&rel=0"><param name="allowFullScreen" value="true"><param name="allowscriptaccess" value="always"><embed src="http://www.youtube.com/v/uJJfCzKbKjA&hl=en&fs=1&rel=0" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>That's the algorithm for our mechanism, simple isn't it??? Now try it with your own imagination, what else this model can do....you decide it.In this dynamic simulation you can do half of your work and cut much of time before advance to prototyping stage, with wide range of application in laboratories for an experiment or in industry by designing some manufacture assembly process even robotic movement which is applying automatic controller, of course with considering mechanical principles</div>

Dynamic Motion Simulation

By continuing my first posting about introduction Vn4D in Indonesian language, now I'll make some simple application for this software to perform dynamic simulation, this is an example for multi-body …

07 Jun 2009

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Static Vs Dynamic Finite Element Analysis

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