Q: Can you suggest some rapid publication journals related to mathematical modelling of soft tissue?
Mathematical modelling of soft tissues is I think a topic related to applied mathematics and material sciences. You could try publishing in material science or biotechnology journals, although some applied mathematics journals might also be open to receiving such articles. I think it would be better to consult your supervisor or senior collegaues on this before you select your target journal.
Publishing in a rapid publication journal is a good decision as it gives you a competitive edge by providing greater visibility to your research in a short span of time.
Here is a list of Elsevier journals that offer fast publication in the field of Material Sciences including journals like Biomaterials and Applied Surface Science. Elsevier also has quite a few rapid publication journals in the field of applied mathematics like the Applied Numerical Mathematics and the Applied Mathematics and Computation. You can access the list here and select the journal that best suits your research topic.
Alternatively, you can consider using a journal selection service to help you select a suitable journal. Editage has a journal selection service; you can take a look and see if you would like to use it.