Hi Rushabh, It looks like a great start! I'm not very familiar with the hysteresis effect, but I was wondering if there is any reference paper or a specific plan for implementing the force. Also, how do you plan to extend DuffingSpring with nonlinear damping behaviour? I think you've read pull request #26438 <https://github.com/sympy/sympy/pull/26438>, which added DuffingSpring actuator, but as you can see, the current class is built on the assumption that when the linear stiffness parameter (alpha) is negative, chaotic motion occurs. This makes it a rather complex case, so I'm curious how you want to incorporate nonlinear damping into this framework.
Best, Hwayeon On Thursday, 20 February 2025 at 18:16:10 UTC [email protected] wrote: > Dear Jason, > > I hope you're doing well! I wanted to follow up on my previous message > regarding my proposed GSoC project. I understand you must be busy, but I’d > really appreciate any feedback on the refined scope I shared—especially > concerning the biomechanics aspect. > > If there are specific priorities or areas that would strengthen my > proposal, I’d be happy to adjust accordingly. Your insights would be > invaluable in shaping a more impactful contribution. > > Looking forward to your thoughts! > > Best regards, > Rushabh Mehta > On Saturday, 15 February 2025 at 22:24:56 UTC+5:30 Rushabh Mehta wrote: > >> Hello again, >> >> Thank you for your valuable feedback and insights! Based on the >> discussion so far, I’ve refined my proposed project scope to ensure >> meaningful contributions that align with current needs. This remains open >> to any and all feedback. >> >> *Current Proposed Scope* >> >> 1. >> >> *Completing Future Work from GSoC 2024 (H. Kang)* >> - Finalizing and merging the remaining work >> >> <https://github.com/sympy/sympy/wiki/GSoC-2024-Report-Hwayeon-Kang:-Implementing-Specific-Forces-and-Torques#future-work> >> >> from last year. >> 2. >> >> *Expanding Nonlinear Models in sympy.physics.mechanics* >> - *HysteresisSpring*: A spring model incorporating hysteresis >> effects, enabling the simulation of materials like rubber. >> - *NonlinearDamper*: A generalized damping model extending >> DuffingSpring with nonlinear damping behavior. >> - Accompanying documentation, tests, and relevant examples. >> 3. >> >> *Advancing sympy.physics.biomechanics* >> - Implementing the two not-yet-implemented methods in musculotendon >> dynamics listed here by you >> <https://github.com/sympy/sympy/issues/25508>: >> - *Fiber length state* (damped elastic tendon). >> - *Tendon force state* (damped elastic tendon). >> 4. >> >> *(If Time Permits) Additional Extensions* >> - Possible additions like rolling friction, viscous friction, or >> other commonly used models based on complexity and feasibility. >> - Further improvements based on feedback. >> >> *Queries and Next Steps* >> >> Given my limited background in biomechanics, I wanted to clarify: >> >> - Will implementing the musculotendon dynamics methods require >> introducing new geometrical wrapping functionality? >> - Are there specific requirements or high-priority areas within the >> biomechanics module that I should direct my proposal towards? >> >> I’d love to hear your thoughts on this refined scope and any guidance on >> it. >> >> Looking forward to your feedback! >> >> Best regards, >> Rushabh Mehta >> On Friday, 14 February 2025 at 13:44:26 UTC+5:30 Rushabh Mehta wrote: >> >>> Hello, >>> >>> Thank you for your valuable and quick feedback! >>> >>> I completely agree with your point that forces like aerodynamic drag are >>> relatively straightforward to implement, and we want to ensure that any new >>> models we add to SymPy provide significant value beyond simple equations. >>> The goal would be to focus on forces or torque models that are difficult to >>> implement and would save users time and effort. >>> >>> I also appreciate your insights on biomechanics. I will research and >>> study up on muscle models and the challenges around wrapping objects for >>> musculoskeletal models. I’ll definitely keep it in mind as I refine the >>> proposal. >>> >>> Thank you again for your guidance, and I’ll be sure to keep your >>> comments in mind as I develop the full proposal. I will be sure to >>> communicate my progress and queries here. >>> >>> Best regards, >>> Rushabh Mehta >>> >>> On Friday, 14 February 2025 at 13:09:46 UTC+5:30 [email protected] >>> wrote: >>> >>>> Dear Rushabh, >>>> >>>> This seems like a good follow up to Hwayeon's project. You have a good >>>> starting idea to turn into a proposal. >>>> >>>> Keep in mind that adding an aerodynamic force, like simply >>>> 1/2*CD*A*rho*v**2, is trivial to include, i.e. Force(point, >>>> 1/2*CD*A*rho*v**2). If we bother to make a special object for the force, >>>> it >>>> should be something that people have a harder time implementing and takes >>>> many lines of code. This way our object saves them that effort. So I'd >>>> like >>>> to see adding fewer more difficult forces than a lot of trivial forces. >>>> >>>> There is interest from the biomechanics community to have muscle models >>>> and many prebuilt wrapping objects. Muscles wrap around your bones and >>>> soft >>>> tissue in complex geometrical ways and until we have more wrapping >>>> options, >>>> many musculoskeletal models cannot be created. So maybe this is of >>>> interest >>>> to you too. >>>> >>>> Jason >>>> moorepants.info >>>> +01 530-601-9791 <(530)%20601-9791> >>>> >>>> >>>> On Fri, Feb 14, 2025 at 7:05 AM Rushabh Mehta <[email protected]> >>>> wrote: >>>> >>>>> Dear SymPy Developers, >>>>> >>>>> I hope this message finds you well! My name is Rushabh Mehta, and I am >>>>> a computer engineering sophomore at VJTI, Mumbai. I’ve been contributing >>>>> to >>>>> SymPy for some time now, with merged pull requests and a few more >>>>> currently >>>>> under review. Working with the SymPy codebase has been an enriching >>>>> learning experience, and I am looking forward to contributing more. >>>>> >>>>> I am writing to share my interest in working on a GSoC project this >>>>> year to enhance the force and torque models in the mechanics module. This >>>>> project builds upon the work done by last year’s contributor, Hwayeon >>>>> Kang, >>>>> who implemented several foundational classes like LinearSpring, >>>>> DuffingSpring, and LinearDamper. While these additions were a significant >>>>> step forward, I feel the scope of their usage remains limited. My goal is >>>>> to broaden the applicability of these prebuilt classes by introducing >>>>> additional force and torque models that are both versatile and >>>>> representative of real-world systems. >>>>> >>>>> Here’s a rough outline of the proposed enhancements: >>>>> ------------------------------ >>>>> >>>>> *Proposed Deliverables* >>>>> >>>>> *1. Nonlinear Models:* >>>>> >>>>> - *HysteresisSpring:* Extend the Duffing Spring to include >>>>> hysteresis and piecewise nonlinear behavior, enabling modeling of >>>>> materials >>>>> like rubber. >>>>> - *NonlinearDamper:* Model damping forces proportional to v**n >>>>> (velocity >>>>> raised to fractional or higher-order power). This can represent >>>>> progressive >>>>> damping systems. >>>>> >>>>> *2. Aerodynamic Forces:* >>>>> >>>>> - *AerodynamicDrag:* Implement drag forces as a function of >>>>> velocity, fluid density, and drag coefficient. >>>>> - *AerodynamicLift:* Add lift forces for aerodynamic systems, >>>>> incorporating lift coefficients and surface area. >>>>> >>>>> *3. Building on GSoC 2024 Work:* >>>>> As suggested in last year’s project (link to the report >>>>> <https://github.com/sympy/sympy/wiki/GSoC-2024-Report-Hwayeon-Kang:-Implementing-Specific-Forces-and-Torques#future-work> >>>>> ): >>>>> >>>>> - Finalize the *Hill’s muscle model actuator* and add an example >>>>> to the documentation. >>>>> - Complete the *friction example* (sliding block on a rotating >>>>> disc). >>>>> >>>>> *4. Documentation and Examples:* >>>>> >>>>> - Add practical examples to the SymPy documentation, such as: >>>>> - Damped oscillations. >>>>> - Aerodynamic forces in free fall. >>>>> - Dynamic muscle models. >>>>> >>>>> ------------------------------ >>>>> >>>>> *Why This Project* >>>>> >>>>> The expansion of force and torque models will enhance SymPy's >>>>> versatility, making it applicable to a wider range of use cases in fields >>>>> such as biomechanics, aerodynamics, and mechanical systems. >>>>> >>>>> I would greatly appreciate your feedback on this direction. Please let >>>>> me know if there are any areas you think should be prioritized or if >>>>> there's anything I should adjust. >>>>> >>>>> Thank you for your time, and I look forward to your valuable input. >>>>> >>>>> Best regards, >>>>> Rushabh Mehta >>>>> >>>>> -- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "sympy" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send >>>>> an email to [email protected]. >>>>> To view this discussion visit >>>>> https://groups.google.com/d/msgid/sympy/ada5689e-76a3-4d81-ab76-0677061052b2n%40googlegroups.com >>>>> >>>>> <https://groups.google.com/d/msgid/sympy/ada5689e-76a3-4d81-ab76-0677061052b2n%40googlegroups.com?utm_medium=email&utm_source=footer> >>>>> . >>>>> >>>> -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. 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