Modeling permanent deformation during low-cycle fatigue: Application to the pelvic floor muscles during labor

Vila Pouca, M.C.P.
Areias, P.
Göktepe, Serdar
Ashton-Miller, J.A.
Natal Jorge, R.M.
Parente, M.P.L.
© 2022Low cycle fatigue (between two to hundreds of cycles) is associated with large permanent strains and the development of microdamage that can start as soon as the first cycle. It has been identified as a possible damage mechanism in the anterior cruciate ligament and recently was evaluated as a potential damage mechanism at the origin of the pubovisceral muscle (a pelvic floor muscle) near the end of labor. The purpose of this work is to provide a numerical framework that incorporates the effects of permanent deformation due to low-cycle fatigue. Based on experimental evidence, we hypothesize that the microdamage accumulation due to repetitive sub-maximal loading continuously induces macroscopic permanent deformations that adversely affect the tissue mechanical properties and thereby cause stress softening. The constitutive model is suitable for 3D finite element analysis. The model was first tested against simple numerical examples, where quadratic convergence and objectivity were verified. Next, we applied the approach to a human vaginal delivery, employing a transversely isotropic visco-hyperelastic baseline model. It demonstrated the potential of this numerical framework for simulating permanent deformation in pelvic floor muscles during birth. With robust experimental data, this can be an important tool to analyze the obstetrical risk factors for the pelvic floor permanent deformation associated with the development of pelvic organ prolapse later in life.
Journal of the Mechanics and Physics of Solids


Design and synthesis of benzene-fused heterocycles: aminopyridazinones, chromenopyridinones and benzopyrazoloxazepines /
Keskin, Selbi; Balcı, Metin; Department of Chemistry (2015)
The interest in the synthesis of heterocyclic compounds has increased day by day due to their biological activities. This study focuses on the synthesis of different benzene-fused heterocycles. In the first part, we synthesized novel class of compounds, 4-aminophthalazin-1(2H)-ones starting from methyl 2-(2-methoxy-2-oxoethyl)-benzoate. Methylene group in this starting material was oxidized to the corresponding ketoester. Reaction of ketoesters with hydrazine derivatives provided the hydrazone derivatives. ...
Tailoring magnetic PLGA nanoparticles suitable for doxorubicin delivery
Tansik, Gulistan; YAKAR, ARZU; Gündüz, Ufuk (2013-12-07)
One of the main problems of current cancer chemotherapy is the lack of selectivity of anti-cancer drugs to tumor cells, which leads to systemic toxicity and adverse side effects. In order to overcome these limitations, researches on controlled drug delivery systems have gained much attention. Nanoscale-based drug delivery systems provide tumor targeting. Among many types of nanocarriers, superparamagnetic nanoparticles with their biocompatible polymer coatings can be targeted to an intented site by an exter...
GER, M; KARAMETE, BK; BEKSAC, MS; AKSEL, S (Elsevier BV, 1993-03-01)
Objective: To develop a probabilistic computer model to predict the preovulatory days of the menstrual cycle by given hormonal parameters such as follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), and progesterone (P).
Reconstruction of gene regulatory networks
Balcı, Sibel; Akkaya, Ayşen; Can, Tolga; Department of Statistics (2014)
With the development of microarray technology, it is now possible to obtain the concentration levels of thousands of genes at a given time or in a given state. By following the changes in the gene expression levels, the responsible genes for cell differentiation or certain diseases can be identified. Gene expression changes are regulated by the interactions between the genes and their products. Gene regulatory networks (GRNs) identify these interactions using the gene expression changes. There are a number ...
Formulation and implementation of a fractional order viscoelastic material model into finite element software and material model parameter identification using in-vivo indenter experiments for soft biological tissues
Demirci, Nagehan; Tönük, Ergin; Department of Mechanical Engineering (2012)
Soft biological tissue material models in the literature are frequently limited to integer order constitutive relations where the order of differentiation of stress and/or strain is integer-valued. However, it has been demonstrated that fractional calculus theory applied in soft tissue material model formulation yields more accurate and reliable soft tissue material models. In this study, firstly a fractional order (where the order of differentation of stress in the constitutive relation is non-integer-valu...
Citation Formats
M. C. P. Vila Pouca, P. Areias, S. Göktepe, J. A. Ashton-Miller, R. M. Natal Jorge, and M. P. L. Parente, “Modeling permanent deformation during low-cycle fatigue: Application to the pelvic floor muscles during labor,” Journal of the Mechanics and Physics of Solids, vol. 164, pp. 0–0, 2022, Accessed: 00, 2022. [Online]. Available: