Hi Marouane, So in *Define.h* starting from line 160, I did give some explanations on what those components are. I know this is not the best way in the world to make documentations, but before a better one is in place you at least have some access to the information.
To answer your questions, the forces are applied by B on A; the force magnitude and point of action are in the global frame. Thank you, Ruochun On Monday, August 5, 2024 at 6:54:39 PM UTC+8 [email protected] wrote: > Hello, > > Thank you, Ruochun Zhang, for your response; it was very helpful. I have a > follow-up question: In the DEMdemo_ContactChain example, we use the line > DEMSim.SetContactOutputContent(DEME_POINT > | OWNER | FORCE | CNT_WILDCARD); to generate a CSV file similar to the > attached one. My question is, does the force displayed in the file > represent the force applied by B on A or by A on B? Additionally, are the > force coordinates expressed in the reference frame related to the contact > plane or in the absolute reference frame? If they are in the contact > plane's reference frame, is there a way to convert them to the absolute > reference frame? > > Thank you, > Marouane > Le samedi 20 juillet 2024 à 11:15:08 UTC+2, Ruochun Zhang a écrit : > >> Hi Marouane, >> >> Stock output methods *WriteSphereFile *and *WriteClumpFile *cannot add >> contact information to the file. You can instead consider using the >> dedicated method *WriteContactFile*. It will write the information of >> all current contacts (geometries involved, contact point, force >> magnitude/direction, etc., and you control what goes to the output by >> *SetContactOutputContent*) to a file. Then you post-process the file to >> get the "contact map" you want. *DEMdemo_ContactChain *is an example >> that uses this method. If you have trouble interpreting the output contact >> file, please post on the forum. >> >> I'd like to add that if you just need the contact pairs (IDs) and the *total >> *force each clump experiences as a result of all the contacts >> surrounding it, there's another approach. *DEMdemo_Indentation* uses >> *GetClumpContacts >> *to query the IDs of the owners that are in contact with each clump, >> then use this information to build a "contact map." Then the *total *force >> of each clump experience can be extracted via trackers. The caveat, as I >> mentioned, is you cannot easily get *each *force pair concerning a clump >> because it's stored in a different way in memory to improve efficiency. >> >> Thank you, >> Ruochun >> >> On Saturday, July 20, 2024 at 12:51:03 AM UTC+8 [email protected] >> wrote: >> >>> Hello, >>> >>> I'm currently working with the DEM-Engine for simulating granular flow, >>> similar to the scenario in DEMO_Hopper_Cylinder_sphere. In this demo, the >>> generated CSV files include data on position, radius, velocity, and family >>> for each particle. What i want to do is to add contact forces : >>> Specifically, for any given particle (let's call it Particle A), I want to >>> identify all particles in contact with it, record the force exerted by each >>> contacting particle, and include this information on the same dedicated >>> line of the CSV file for Particle A. Is there an existing method or >>> approach that would allow me to achieve this? >>> >>> Thank you! >>> >>> Marouane ELBISSOURI >>> >> -- You received this message because you are subscribed to the Google Groups "ProjectChrono" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/projectchrono/2a2e2d51-6f73-4cc4-b52b-37a8af1725c8n%40googlegroups.com.
