Elastic Strain, Plastic Strain and Hysteresis

When you add weight to a rubber band, it stretches. When you remove that weight, it returns to its original shape but not along the same path. As you remove the weight incrementally, the band contracts slightly less than it was stretched until the last weight is removed – this property is called hysteresis. If you were to observe a diagram of the stress and strain during the loading and unloading, you’d see a loop – as long as the strain was only elastic. If you add too much weight, you get plastic strain and permanent deformation.

Woman are like rubber bands: physically, mentally, emotionally and spiritually. We take on all sorts of strain – pregnancy, birth, raising children, sickness, crisis, challenge, loss, etc. On the most visible level, during pregnancy we get huge over a span of nine months. We hope to return to our original shapes within two months, but more often it takes two years… and there we have HYSTERESIS. The swelling and shrinking tummy is ELASTIC STRAIN. The stretchmarks on our hips are a perfect example of PLASTIC STRAIN.

Mentally, emotionally, and spiritually this is harder to understand. In someways, I feel forever changed. My mind has permanently changed. I am not as quick on my toes academically, but when it comes to noticing household hazards and keeping track of all things baby and toddler, my brain has an amazing way of being able to multitask. Now considering I am dealing with postpartum depression which is caused by chemical changes, I’d say the jury is still out on the emotional/spiritual changes. I feel very stretched, sometimes to a point of breaking.

However, I can’t imagine that deeply emotional experiences are meant to do anything BUT to change us permanently. Relationships and breakups in college forever changed me. Marriage has forever changed me. The same is true of pregnancy, childbirth, and miscarriage… disappointing friends, being carried by friends, taking my child to the ER, buying a house, losing and gaining community.

I don’t expect I will ever return to where I began, mostly because like a rubber band I’ve been stretched and released many times over, sometimes by weights that caused permanent changes to my physical, mental, emotional and spiritual structure. However, unlike a rubber band which eventually experiences fatigue, I grow stronger given proper rest and nourishment (and sometimes good meds). This is one of the many beautiful things about women – we stretch, we change, and we grow. I look at my mother and other women who have carried burdens much heavier than my own and I see how beautiful and wise they have become. I am so tired right now, but I hold onto that hope that there will be a time when the strain lets up for just a moment to catch my breath and prepare for the next load.