CAD - Science topic

Is their any FE modeling software to create porous structure in any solid model.

Basically I am designing acetabular cup in CREO on which i want to create trabecular porous structure on articulating surfaces. But I am unable to create porous structure in model.

I tried in ANSYS too but failed.

Any suggestion please..

Hi everyone,

I work on Abaqus for a project and I want to optmise a part (topoogy + shape). I created the model an ran the topology optimisation. Now I want to extract the result geometry to make some shape optimisation. Is it possible to make it directly from Abaqus or with a Pyhton script or do I need to convert it in a CAD software ?

Thank for your help

So far world knows agile has emerged from IT/software solution projects. The methodology/ concept of agile is so highly effective that companies now want to explore its scope in managing mechanical product development.

1 biggest challenge i see before even embarking on the concept is, having an agile approach in CAD. A CAD engineer will take several days in general to modify or create a new model. Similarly, FEA/CFD will take days to iterate constraints to reach a solution. This cycle time is too big to go the agile way. How can we break down this work chain and check midway to make sure the progress is in right direction and effort will not need a redo?

Mechanical engineers are orthodox in working pattern so to say. There has been many improvisations and upgrades in CAD software but none in working style or thinking style.

Hello dear colleagues,

I want to reproduce the surface topography of metal additive manufacturing samples in CAD and CAE environments. What is the best way to capture surface topography and how can I reproduce it?

Any recommendation is appreciated in advance.

Best regards,

Hamidreza

I have designed a digital circuit using an all-optical logic gate using R-Soft CAD layout and the output achieved for logic 1 is only 6% of the maximum normalized power. i need to improve it.

is there any possibility in R-Soft CAD layout to design an amplifier.

Can anyone say how to design amplifier?

Hi,

A part of my research project is to obtain the strain distribution of a certain geometry that has one flexure. I define flexures as localized thinness that occurs in a constant thickness geometry (CAD picture attached). For my case, I am looking at a flat beam and a hollow cylinder with one flexure that is 5 cm wide and 1 mm thick, and there is a smooth transition from 2mm thick to 1 mm thickness. I am using ANSYS mechanical (static structural simulation) to get the strain distribution. I have also attached the plots that I got for both of the cases. My question is, for a flat beam, there is a clear rise to a higher strain value where flexure is placed, however for the cylinder case, there is a dip first, and then strain rises and then flattens out and then rises again, creating this "Batman ear" looking shape. I do not know why it happens. So I was wondering if anyone here has any idea or possible explanation. The geometry is set up the same: one end is fixed, and a point load is applied to the free end. The material for both of the case is ABS plastic. Thanks, in advance.

PhD research student, Looking for blades in particular to a long distance aircraft engine.

Please contact me.

Alternatively, please let me know if there is a used blade available for me to get measurements from.

There are CAD available on GrabCAD but not able to validate and verify.

Hi,

I have an experimental tensile curve. This is the engineering stress strain curve right?

I have then converted it to a true plastic strain curve using Abaqus material conversion. Using these values, I have run a tensile simulation.

However, the results that I have obtained seem to replicate more of the true stress strain curve and not the experimental curve.

The load is displacement based where it is pulled by 32 mm which reflects accordingly to the experiment.

I have plotted misses stress vs LE11.(logarithmic strain along x direction ).

The peak stress in the experiment is 50 MPa while the peak stress for the true stress strain is 70 MPa.

I have attached my results below.

From the simulation, I am getting 70 MPa also which is not representative of the experiment.

Is this how its supposed to be or am I skipping something?

Thanks in advance for your help!!

Hello,

in my research group we would like to evaluate how the asperities of two rough planes deform when we press them together. We would like to use Abaqus, due to its advanced contact mechanics algorithms. It is not clear to us, though, how to model rough surfaces with certain statistics in Abaqus. Anyone knows any CAD software/code that could generate these models and be easily integrated with Abaqus?

Best regards,

Rafael.

Dear Colleagues, I would like to start a research on automatic drawing for the peruvian high voltage power grid; could you share with me papers on the subject? The purpose is to use the node/branch data for load-flow to draw in a CAD software the one line diagram. Any help is welcome. Best regards.

Carlos Muñoz Medina

Universidad Nacional de Ingeniería

Lima, Perú

Thomas Hughes' original NURBS representation has several limitations such as grid morphology, inability to incorporate holes, global refinement, etc. To address these shortcomings, other formats such as T-splines, LR-BSplines, U-Splines have been proposed. In your knowledge, what approach shows the best potential for versatility, robustness and ease of implementation?

Are there any existing tools that would allow to compute Signed Distance Function (SDF) directly on a CAD shape without it being tessellated?

It seems that such solution would be more efficient than meshing and calculating SDF on triangles. Also, as far as I understand, a lot of CAD design softwares use implicit representations for boolean operations, however, I did not find any package that would allow to extract such implicit representations from CSG CAD formats.

Hello,

I would like to extract all the walls from complex .DWG files that comes from the conversion from a .PDF by AutoDWG software. In these big multi-floor plans, there are multiple types of walls (exterior, office, corridors, etc) that have their own thickness and interior composition (trusts, insulation, etc.) and it's not even always clear to the eye where one type of wall ends and another starts. To give you an idea of the problem, here are two examples of very small regions of these kind of plans.

Note that I'm NOT interested in starting from a high resolution image of a scanned floor plan as the information is already vectorial in the DWG file. Also, I must do it by programming and as little user intervention as possible as this must be part of a bigger software solution.

I would be glad if anybody could propose software, libraries or papers describing methods to extract wall information from such a .DWG file. I guess OpenDWG seems to be part of the solution but if someone has more first hand experience with this problem, I would like to know about that!

I was trying to perform boolean remove to make a solid of the interior space of this muffler. To simulate the fluid passage inside this muffler I need to create a solid of its interior space but, the problem is that removing the remaind solid is not easy. Any idea or trick to remove them as quick as possible?

I can't find in The NURBS Book.

Hi Sirs,

I am trying to design an intelligent controller using GA, ANN, ANFIS or FLC, to control a 3D Computer-Aided Design (CAD) assembly of TRMS i did in SolidWorks. Is this practicable and can anyone give me any clues how to go about it. I'll really appreciate it Sirs/Ma, cos I have been stuck here for quite a while.

Cheers

AutoCad and Solid Works are two of the most famous CAD software for Engineering Design.

I've done the airfoil CAD and the C-Domain mesh using design modler, then imported it into fluent, but apparently it expects to see 3D zone with 3D cells, so that's why it says there aren't any cell zones.

I've tried to set the geometry properties from workbench to 2D, and tried to start fluent meshing in 2D but it only starts in 3D

I am trying to get the real dimensions of the extruded part in deform-3D but I cannot. So, I get as idea about export the deform file as iges file format or any other neutral file formatting to reat it in CAD program and get the dimensions

I'll need to research on this but I am a beginner and need to learn from the start. So, I hope someone can give me like a starting point. I've searched a lot, and there are a lot of ways of doing this, but on what way it can still be improved? I hope someone can help me on this.

Does anyone have experience with creating objects in 3D from a point cloud?

We have a very detailed point cloud displaying a geological structure - but in the detail level of what architects are used to. To deal with it in a CAD-software, we need an importable 3D object ... which is quite a task considering the level of detail.

(Why we don't create a mesh first? - We can, and we did, but the mesh needs to become an object anyways to be read by our CAD-software.)

Collecting and publishing medical image datasets is an important task contributing the development of CAD systems for different diseases, but What kind of problem can we face after publishing it. for example if one of the cases is miss diagnosed.

Collecting and publishing medical image datasets is an important task contributing the development of CAD systems for different diseases, but What kind of problem can we face after publishing it. for example if one of the cases is miss diagnosed.

Digital Twin NEWS! -ISO-IEC-JTC1-SC41-IoT has launched its Digital Twin framework standardisation at its Nov. Plenary. -Edge Computing & Networking, from VLSI to AI and back, in real time when needed, is essential in this endeavour, with specifications from ETSI (ETSI-ISG-MEC: Multi-Access Edge Computing), 3GPP and One M2M supporting this goal. Cyberphysical systems benefit highly of Digital Twins for optimised fault-tolerant operation, verification and validation, simulation, in particular. -Combining functionalities tightly is a must: software, efficient/secure and sustainable data handling, computing and networking may have to be jointly managed, and possibly integrated at every node of a system using fully Digital Twins.

Speed and energy efficiency are available from VLSI chips integrating two functional layers as the IMX500 from Sony: -Data layer: interfacing to the real world (analogue to digital sampling, and digital to analogue rendering, "data I/O" layer)

-Processing layer ("logic" layer) e.g. with AI algorithms to build or prepare decisions from the data acquired, and conversely to manage and implement decisions into the physical world.

Use cases include smart city functionalities, cognitive design/manufacturing, autonomous systems/vehicles.

What is your view on Digital Twin, in what role is it best positioned? Design? Operation? Fault correction? Other?

Allow me first to apologize in advance for the long post. I have tried to keep it right-to-the-point as possible!.

Objective

To simulate suspension of solid particles using CAD software/create a medium with a concentration of suspended particles in the air.

However, I would like to give everyone a heads up; I am of little to no experience with anything pertaining to CAD softwares - though I have started reading about and experimenting with it end of last year - and this marks my first attempt to include it in my ongoing research 🙏🏻

A chamber of a particular shape – such as cubical, cylindrical or spherical… etc.

The shape is projected to have an air inlet (an opening connected to a fan) to blow a certain quantity (e.g., in kg) of solid particles (mixtures of diameters, if possible) positioned at the bottom of the chamber prior to investigation.

Is it possible to..

Ansys 2020 R2 (student version) and Solidworks 2018 (with flow simulation add-in).

I have taken the liberty of exploring various sources to get a hold of some drawing and simulation basics using the aforementioned CAD tools in addition to familiarizing myself with some terminologies.

However, I found myself drawn to solidworks more than any other program due to its simplicity and user-friendly GUI. Using solidworks and its flow simulation add-in, I have managed to draw basic shapes (such as a cylinder with an inlet pipe) and conducted some air flow simulations, but without validations.

Unfortunately, that’s the maximum I can achieve within a reasonable time and any further attempts to figure out the meaning/inclusions of additional parameters maybe time consuming. Therefore, I would appreciate any comments/feedbacks/guidance that could steer me in the right direction.

Looking forward to your kind replies :)

Stay safe 🙏🏻

My lab is considering purchasing a TipNovus (https://www.grenovasolutions.com/tipnovus/) to clean and re-use pipet tips. We're basically wondering if it works as advertised, and there don't seem to be reviews online. Some questions we have include:

- How many times do you re-use your pipet tips using the system before they have to be thrown out?

- Are you confident that the tips remain sterile and don't get slightly misshapen from the washes, which could compromise their accuracy in pipetting?

- Is there any waste generated from the cleaning reagents?

- And most importantly, overall would you recommend buying it? A company sales rep has given us a quote of $80 000 - 155 000 CAD (60 000 - 117 000 USD)

I need Coronary Angiogram Images(CAI) publically available dataset.

Coronary Artery Disease (CAD) is a condition of the heart due to atherosclerosis. Atherosclerosis is the narrowing of arteries (Aorta, LAD, LCX, RCA) of the heart because of plaque formation, due to cholesterol and fat penetrating the inner walls of arteries. Early diagnosis of CAD is very important if unattended leads to heart attack/death. Coronary Angiogram Images(CAI) are used by physicians in the penetrating to identify exact status of CAD.

Good day everyone

currently I'm using Rsoft CAD as simulation tool for a Y-splitter, and I have a case when the launch field TE1 and the patway monitors the launch power, byeond the split point, the field vanished. while it gives reasonable readinds when the monitor for slab mode power.

which one is correct? can I consider the slab mode power?

is there any way I can modify the monitor to read the launch power correctly at the end of the structure?

attached s the case I described.

I need to generate a mesh over the surface of a 3d object consisting of a number of intersecting cylinders. This needs to be done repeatedly, within the loop of an optimization. I'm hoping there is a simple and free tool out there that could handle the task, so I wouldn't have to make my own. (Panelizing the cylinders is easy, but making an algorithm to deal with panelizing the intersections would be too complicated to code myself.) Are there any such software tools out there? Ideally something that could be called from within matlab or a c++ code?

Hello everyone,

in the context of my dissertation I am trying to find out how product development will change with regard to additive manufacturing. Will product developers have identical workflows in 5-10 years, or will parts mainly be calculated and geometry created automatically?

In order to better understand these and similar questions, I developed a short survey, which mainly includes the use of alternative programs for geometry generation and the product development process itself.

I would be pleased if you would take a short time to answer the survey.

Dear all,

I am trying to apply material mapping to the vertebral model. I exported image data and surface model (.stl) from the 3D slicer, but when the same are imported IA-Femesh, there is no overlap, so cannot apply the image intensity based properties.

Can you please help me to resolve this issue.

Is it possible to link the IA-FEMesh to 3D slicer?

Hi, I wondered if you could spare a few minutes to watch this short video of a prototype Predictive CAD system (created by our research project) and answer some questions afterwards?

We are interested to get thoughts and reactions of a wide range of researchers, engineers and industrial stakeholders:

https://www.surveymonkey.co.uk/r/5SD2H8Z

Many thanks

Prof Jonathan Corney

Try to found a group.

I tried to simulate an antenna design in cst software. I got such error as shown in the picture. Please solve my issue.

I want to draw a shape of piston (that is attached) in Auto CAD and save it in dxf format and then import it in AVL Fire in ESE Diesle part.

after draw it in CAD when i import it in ESE occur an error

''contour in piston file is not closed''

I don't know how exactly draw it in CAD?

with pline, spline or ....?

how to close the shape of the attached file in CAD?

as you know i draw it in 2D.

Many thanks,

Masoud

Greetings everyone,

Would anyone be able to suggest or know of software to model the dosage of UV received by a surface from a source object? For example, I would like to model how a cylindrical UV light bulb emitting UV-C at 254 nm at 4 W irradiates the surfaces in an enclosed, reflective space of various geometries.

What are the advantages and disadvantages of the manual design process of cars and tractors, and how do you assess the advantages and disadvantages of using CAD systems in the design process?

Whether you're making stuff physically or virtually, you ARE making stuff. Don't take my word for it, see what the U.S. Department of Labor has decreed: https://dasisolutions.com/appreticeship-program

I plan to use V-REP together with python for the development of trajectories in 3D CAD models, the path I will trace on the CAD file and generate a DXF file of it, Python would process it to enter the trajectory in V-REP.

Would someone recommend me any resources to learn how to program V-REP? Or how could I link between the DXF file, Python and V-REP?

Hello, I wish to obtain CAD for any NUMISHEET benchmark models to validate by friction model. Any help in this regards in appreciated. Thanks.

I had tried several methods but was unable to carry out a FEM analysis of braided sleeve. Anyone who has knowledge about this, please help. The image of the sleeve is attached so that it might give you an idea.

For a senior thesis I am designing an open structure (think kiosk, pop-up shop or other semi-permeable shelter) which will primarily feature a solid roof and basic support geometry. The roof will be pitched and the model will need to illustrate attachment of photovoltaic panels and rainwater re-direction. The structure is designed to securely contain 3-4 machines about the size of 10 gallon paint buckets; the enclosure of which will require some basic moving parts i.e. hinges.

Material possibilities: Extruded and/or corrugated sheet steel, aluminum, wood, concrete, mud/thatch.

While I have some experience with SolidWorks, I have mostly designed small products as opposed to structures and am wondering if I should try modeling in Rhino or another program instead. As a student I should be able to access any program on a trial basis at the very least. If anyone with experience would lend some insight that would be greatly appreciated!

What is the best way to import 2D cad geometry from Creo to Comsol Multiphysics?

I am extruding entity in assembly mode in creo. The feature is generated but not displayed.

Is there option to unhone or display.

I'm trying to import CAD files ( saved in version 2014) to Monde beta 1 in ENVI-met 4.4.4 but nothing is loaded. The area is approx. 500*300.. is there any recommendations / help with this problem ?

I also check the Monde YouTube tutorial but it doesn't help

I need to simulate the transmission loss along a vent that is coated with acoustic foam. Since i´m still waiting to have access to Ansys, i would love to know if there is some free acoustic simulator that would allow me to import CAD files and run simulations to determine the transmission loss for different frequencies band

I am new to using ROS MoveIt, I want to know how to load 3D CAD files of industrial parts to perform the actuator trajectory based on the cad file.

I want to do a numerical study of ship propeller. I can make a random 3D propeller model using CAD softwares. But is there any recomended propeller models or detail information of any propeller geometry - blade shapes, angles, dimensions etc?

Dear All,

I am a kind of new to startCCM and I am going to model a geometry which I have taken data from MATLAB regarding the points and lines. However, when I get through imprinting to make a sheet over lines, I came across an error said" Open wireframe. Please check the input sketch". It would be really appreciated, if someone let me know how to manage this issue. The relevant photo is attached.

Hi, I'm trying to find out the velocity, force and pressure of the blood flow as it enters the needle during the puncture of the AV fistula. It could be a 14G needle for example.

I want to draw a waveguide which is tilted from one side only on Rsoft beamprop CAD. anyone know how to draw it as in Rsoft when i tilt a waveguide it effects on both sides of the waveguide.

I am interested in the numerical characterisation (3D-CFD) of aerodynamics and flow-induced noise (near-field) generated during the operation of a standalone horizontal axis wind turbine. Since I am attempting this activity for the first time, I was wondering if there are any publicly available CAD and performance data of any test wind turbine to validate the numerical methodology.

On a side note, if anyone could recommend me some pivotal pertinent literature, it'll be a great help.

Also, as my knowledge on the state-of-the-art is limited, I was wondering about the practices for modelling impeller rotation. I understand that specifying an angular velocity to the rotating domain should be relatively straightforward but are there any literature/methodologies available to model the motion of the blades based on air-velocity boundary conditions.

Thank you for reading and contributing.

I'm working on CubeSat Antenna design, when I put the Antenna attached to the CubeSat all the results become low such as the Gain and Efficiency .

The CubeSat is made of Aluminum I made it in CST Software , But when I use a Cad file for the CubeSat and import it to the CST and put the antenna above it the antenna will work fine .

Is it wrong to use a CAD file as a CubeSat with My Antenna Design ?

Is the particular  implementation results for the Antenna will be the same as the simulation results  when using a CAD file as CubeSat ?

Thanks in Advance

Geral Farin [1, page 119] mentions that B-splines were investigated as early as the nineteenth century by Nikolai Lobachevsky at Kazan University in Russia.

[1] Farin, G. E., & Farin, G. (2002). Curves and surfaces for CAGD: a practical guide. Morgan Kaufmann.

What are the most important discoveries in geometric modeling in the last 30 years?

Please share your opinion.

Thanks.

Dear all,

The new winter release of ENVI-met offers many new possibilities. Among others, instead of 'building a model' in SPACES which is rather time consuming, Monde offers the posibilities to import a GIS shapefile, a CAD file or even a Streetmap file. To my knowledge, no tutorials on Monde are available yet. Does anyone have experience in working with Monde? I am mostly interested in working with Streetmap data.

Regards,

Anke

What is the rationale behind co-administration of Ticagrelor 90mg once daily together with Apixaban 5mg BID for patient with stable CAD despite the major drug interaction and risk of bleeding? Is there any clinical evidence for that?

Are there any papers that compare the difficulty of learning and using Engineering software (CAD, CAE (Engineering Analysis) and CAM) with general office suite software (e.g. MSOffice software)?

I am trying to install TCAD for my thesis work but its not working properly, Maybe I am missing something.Tried to figure it out but I couldn't.

Hey all !

I want to select offset nodes in ansys APDL from a irregular surface uniformly. I tried selection logic but failed because constructed surface is not in defined coordinates (PFA picture).

In my case i want to select all nodes uniformly from the surface nodes to the distance of 1 but failed. 

Kindly help me

Thanks

Nishant

Dear all,

For a project I am currently working on, the intention is that I calculate the maximum allowable pressure in a rectangular 'pressure vessel'. Of course this shape is not suitable for a real pressure vessel but in this case it is considered as such.

From CAD software I made a simplified model of the pressure vessel and loaded it (.stp) into ANSYS. When I apply pressure from the inside to all walls, the simulation only gives stresses in the upper plane and in side planes 1 and 2 (these sides are opposite to each other). I fixed the bottom side but the sides 3 and 4 don't show any stress or deformation, this is not how the real situation will be.

Two 'warnings' come up when solving the simulation:

1. Two or more remote boundary conditions are sharing a common face, edge, or vertex. This behavior can cause solver overconstraint and is not recommended, please check results carefully.

2. One or more MPC contact regions or remote boundary conditions may have conflicts with other applied boundary conditions or other contact or symmetry regions. This may reduce solution accuracy.

It seems that the model is overconstraint but I am not sure how to model proper contact definitions for this model. The current situation is done by creating automatic connections between overlapping contact regions.

Does anybody have tips or solutions to this problem?

Thank you in advance.

Kind regards,

Bart

I'm an intern in a company working on my M.Tech. thesis. I am supposed to be working on "Forced response analysis of Gas turbine blade". But turns out that the proper problem definition on which I can work is not available with the hiring team. I need to find a turbine blade whose data is available (with CAD geometry) for public use. I need to use the geometry in my thesis and use it for research work. If anyone has the idea in this regard please share ASAP.

Dear All! I need NASA Rotor 37 CAD geometry. Please send me the CAD geometry. Thanks in advance

Hi

Can anyone help me to answer that is it possible to convert a SEM image in form of CAD file in some commercial software such as ABAQUS?

I am designing very complex designs that need to be simulated and tested on a design software

i have a 6 machines computer cluster with a 64 GB RAM and 1 TB HDD each

what CAD software do you recommend using?

Many simulation software's are killing the basic knowledge one should have of his field but use of these software's are sometime more helpful and productive then the theoretical knowledge, what you people thinks?

Hello,

In a new project I'm about to start in the garment design industry, I will need to extract some surfaces from the scanned body of a person in order to customize parametrized pieces of clothing based on these surface measurements.

I already used Rhino on another manufacturing project. All its algorithms can be called from Python scripts and reusing its visualization, object creation, geometric algorithms was a big time saver.  The problems I encountered were the following:

- Non standard Python 2.7 version (Iron Python) not compatible with lots of recent libraries (difficult to use NumPy, SciPy, etc).

- Non robust mesh algorithms (intersections, boolean operations, etc.)

I would like to get advices from people using other CAD like CATIA, SolidWorks, Pro-E, etc about the ease with which one can extend and customize these software to serve as "frameworks" for custom applications.  Which language can be used? Can it call standard C/C++ code or Python code?  Are they offering advanced and robust algorithms on triangular meshes?

Thanks

Dear all

I am trying extract the volume of a CAD drawing which is a surface body (no thickness). When I want to extract the volume in Designmodeler or spaceclaim, it says it should be a solid body. Since the geometry is complicated, I dont want to give a thickness to the geomtery. Can somebody help me in this case?

Hassan

Dear guys,

Can anyone help me with understanding that How I can develop a 3D Cad model initially made by Mimics. I can develop a 3 model at Mimics, however my problem is I do not know how to create a solid 3D model which I can use at Catia or other CAD software.

Thanks

ERROR: A Not-a-Number (NaN) value was computed for the integration error. This problem may be related to wrong values computed by user-written subroutines. Please try using the Adams utility subroutine NANINF.

the model consists of 2 pairs of gears and shafts

for early detection of MI showing highly specificity and sensitivity marker i want to do case control study of CAD patients i want to know the correct sample size

Can any one advise what software package is best to simply deform part/all of a 3D model, without going through all the hassle of surface editing, etc.?

Background:

1- I have a nominal 3D model from which we cast a metallic part

2- during casting/solidification some distortion and shrinkage happens which is not uniform and depends on the sections thickness and shape

3- I'd like to negative the distortions and scale up the shrinkage on different sections on the nominal 3D model to generate a new 3D model for casting, so that the final as-cast part (which shrinks and deforms) gets closer to the nominal shape/dimensions.

i have treated the both and didn't really noticed any big difference. its just the size of the incision which will make the pt feel more pain. unfortunately, i couldn't find any articles regarding pt management for such case and i do believe sooner or later this case should undergo for research.

I am trying to get the simulated data for Mechanical properties of (Stress/strain/ fatigue failure) a CAD speciment made of Nitinol (Nickel titanium alloy) after & before cryogenic treatment.

I have imported this model from a CAD program. I am having difficulty meshing it. I would really love any suggestions as to how I can go about achieving the following :

1. The model is symmetric about the Y axis. That means the nodes on the left side and right side faces (as marked in the figure) need to match. How do I go about doing it?

2. Is it possible in Abaqus to create a Hex/ Hex-dominant, conforming mesh for this model? If so, could you name a few methods in which I can do it?

Thank you so much for all your time in answering my questions!

Hi,

I'm looking to draw copper tracks on a double sided substrate within a software that allows me to export as dxf/dwg/gerber for fabrication. Can anyone recommend a pcb design software that allows me to draw on copper tracks as oppose to just dragging and dropping circuit components?

Thanks