​Stress and strain are fundamental concepts in engineering and materials science, describing how materials respond to external forces. Understanding the difference between stress and strain is crucial for analyzing material behavior under load.

Stress is defined as the force applied per unit area within materials. It quantifies the internal forces that particles of a material exert on each other when an external force is applied. Mathematically, stress (σ) is expressed asσ=FAσ = \frac{F}{A}σ=AF​​

where FFF is the applied force and AAA is the cross-sectional area over which the force is distributed. The SI unit for stress is the pascal (Pa), equivalent to one newton per square meter (N/m²). Stress can manifest in various forms:​

• Tensile Stress: Occurs when forces act to elongate a material.​Compressive Stress: Arises when forces act to compress or shorten a material.​
  
• Shear Stress: Develops when forces are applied parallel to the surface, causing layers within the material to slide past each other.​
  

Strain measures the deformation or change in shape of a material in response to applied stress. It is a dimensionless quantity representing the ratio of the change in a particular dimension to the original dimension. For linear deformation, strain (ε) is calculated as

ε=ΔLL0ε = \frac{\Delta L}{L_0}ε=L0​ΔL​​

where ΔL\Delta LΔL is the change in length and L0L_0L0​ is the original length. Strain types include:​

• Tensile Strain: Associated with an increase in length due to tensile stress.​
  
• Compressive Strain: Related to a decrease in length resulting from compressive stress.​
• Shear Strain: Describes the angular distortion occurring from shear stress.​
  

The relationship between stress and strain is often depicted using a stress-strain curve, which provides insights into a material's mechanical properties:​

1. Proportional Limit: The initial linear segment where stress and strain are directly proportional, adhering to Hooke's Law.​
   
2. Elastic Limit: The maximum stress that a material can withstand without permanent deformation.​
   
3. Yield Point: The stress level at which a material begins to deform plastically, leading to permanent deformation.​
   
4. Ultimate Stress Point: The peak stress the material can endure before failure.​
   
5. Fracture Point: The stress level at which the material ultimately breaks.​
   

Understanding these distinctions is vital for selecting appropriate materials and designing components that can safely withstand operational stresses without failure. For more information https://scienceinfo.com/difference-between-stress-and-strain/

Long post alert, I’m sorry in advance, but thank you sooo much to anyone who takes the time to read and offer ideas.

Help! I’m a mom of two, ages 16 and 9, and I work full-time in a high stress job (I love my job, it’s just naturally stressful). I regularly get so stressed out that I get overwhelmed and essentially feel like I can’t function or take a deep breath. I describe it as “I’m so overwhelmed I can’t think”. My kids are a big cause of it because even when I’m starting to get overwhelmed and try to take a little while to try and calm down and ask them to leave me alone temporarily, they don’t. They’re old enough not to need me every second, so you’d think I could get even just like 30 minutes to relax between work and then my evening duties with them and house chores, etc... but it’s just non-stop, like every couple minutes non-stop, even if they promise they’ll leave me alone just for a little while. I literally can’t even go to the bathroom in peace. They just do not stop. Either they’re fighting or want to tell me something that could’ve waited, etc. I feel like I can’t even take a deep breath most of the time. Even when my husband is around, they constantly come to me and not him. He tries to help, but they just don’t give me a break. We all need and deserve a break right?!

(For the record, I absolutely love my kids, I’m super involved and proud of them, at every event, they have busy schedules of their own, have everything they need, etc. - it’s just no one can juggle it all without time to essentially take a dang breath)

So all that, plus the natural stress of a job, marriage, bills, chores, etc.

All that is to say… anyone with high stress like me… what works to actually, truly relax you and help you feel better? I’ve tried various things over the years, including: relaxation techniques, taking up hobbies, listening to music, taking a nap, watching tv, playing video games, going bowling, getting a massage, getting my nails done, reading, writing, etc. I’ve tried sooo many things that interest or should relax me, but nothing makes me any more relaxed or any less overwhelmed. At all.

Physically, it takes a toll too. I suffer from severe, chronic tension in my neck and back, waking up with constant tension headaches that I have off and on all day and night, near constant need to take Advil and Tylenol to prevent or treat the tension headaches… high resting heart rate. No high blood pressure (surprisingly).

Has anyone been stressed to this point and what ended up working for you? Thank you!

Didnt realize I was overworked until I took my first vacation in about 5 years. I slept 6 hrs a day, drank alcohol, ate whatever I wanted, worked out maybe twice in two weeks. My body had never felt better, i didnt feel tired, all the aches/pains/migraines went away.

First week back to my crazy schedule and I’m realizing between working 10 hr days, 2.5 hr commute, 6-7x per week that all my health issues may be cause due to stress.

I think the nature of my job is considered one of the most stressful jobs in the world and I love it but I need to find a way for this to become sustainable.

Some things I’m working on -

moving for a shorter commute will save me tons of time and actually making time to gym not obscenely stressful.

also working on building a home gym to make that easier

I’m committing now to 8 weeks worth of vacations per year and adding it to the budget. Probably all-inclusives to chill.

These are all long term stuff though, what can I manage in the short term day-to-day?

He blamed everything on me, while he is the one who created the situation. He used to meet with me once per 2 weeks, now he meets me once per month lol, which is clearly a situation of lack of supervision. He said that I am lack of autonomy. In fact, things work in reciprocal. I'm the executor, I'm working at the most basic level, I need at least some guidance and direction. I work alone with my big bro sometimes accompanying me and guiding me. Things are terrible.

Key example. I did something, he didn't see it, and he said that I didn't do it. Things are so small seems so big to him. Dxxn, fxxk. I hate him.

I'm absolutely 100% not stressing about anything and entirely in love with my life. My life is an amazing joyous thing that fills me with energy and happiness.

Take a Break from Screens

Too much screen time (especially social media) can be overwhelming. Step away for a few minutes to reset your mind, close your eyes or look at something natural like plants or the sky.

What are your favorite hamantaschen fillings? Unique or classic? One of our (adult) kids loves salted caramel (you have to make the shell, and pour in as the cookie cools).

Do your kids have costumes picked out? Are you planning on attending a carnival?

Share all of your budget friendly, low stress plans and ideas!

What does everyone enjoy doing for St Patrick's Day?

Does your city have a parade?

Do you make any fun green themed snacks?

My favorite has always been helping my kiddos make a leprechaun trap!!!

Hi everyone, I’m hoping this could be of some help to me or at least some encouragement.

I’m 27F and husband is 33M.

My husband has had a chronic illness for a year and a half. He will heal from it but it could take up to 3 years according to the doctor. It’s pretty dire right now, we barely talk, he doesn’t know anything that goes on in my life so I’m feeling pretty neglected as a wife and yet I have to do EVERYTHING to keep us afloat. I have to work full time, have meals prepared and in the fridge for us, so have to cook and clean the whole house by myself and do every single other thing life throws our way ALONE (but I’m carrying him as well as myself). I’ve done really well tbh. But I carry so much anger, sadness, and resentment. I’m ambitious but I can’t plan the future because I don’t know where we’ll be in a years time. I don’t know how long it will take for us to rebuild as he can’t work at all right now.

I have family and friends to talk to but honestly just nothing feels like enough for me because I’m so tired of everything.

Anyway, I have recently turned to vaping. I’m super healthy food wise, started gyming a few months ago, and love all things natural. So this is really not like me and of course I feel conflicted even doing it. I haven’t told a soul. After I vape I get body aches too??

I just felt like I needed some sort of vice to help me in the times where I feel so angry yet nothing can be done about the situation. For example, he has extreme noise sensitivity - where even me washing the dishes downstairs with him being upstairs is too much for me and I have to stop. It angers me so much because I don’t even want to ALWAYS have to do the dishes!!!! Yet I have to stop when he says otherwise it flares up his symptoms (it’s a nervous system issue).

So my question is - what can I do to manage my stress???!!! Especially in those moments where I feel like I want to smash something up out of anger and instead, go to my emotional support vape.

Signed, a stressed out lady !!!

So a few months ago, I went through intense stress and anxiety. And ever since then, I haven’t been feeling like myself. I’ve been feeling very disconnected, even from my own hobbies and comforts. It feels incredibly disorienting, like I’m losing my spark of my sense of self and I’m just floating adrift. :( I’m scared, and I’m just looking for advice, reassurance, or guidance on how to navigate this. I feel really overwhelmed and scared.

I want to know what you guys struggle with when it comes to working out, doing fitness, having time for the gym, gym anxiety, meal prep, no schedule, no workout plan. What makes it difficult for you to follow your fitness goals?

I need to know because I am trying to find a solution for this. I am an electrician with muscle building as my hobby and I would like to help other people by getting to know peoples struggles and not just my own.

Thank you guys in advance and here's a little tip to "unstress" after a demanding day:

Sit in your room without light, no music, no distraction and phone on autopilot and just sit there for 5 min and take deep easy breaths. Put a timer on your phone :D

I've been noticing that I have all of the key signs of stress (muscle pains, constantly fast heart rate, headaches, the lot and more) now, I don't really feel stressed in the conventional sense, but I can feel that my body is reacting to stress and I don't really know how to help it.

I've done a couple of those smartwatch stress tests and all have been top of the scale in the red zone, how can I bring it down? I don't want it to become a serious problem but I have no idea what's causing it either, any advice?

Thank you.

“My son turns 18 tomorrow, and while it’s such a milestone, I’m heartbroken that I can’t make it as special as he deserves. He’s graduating this year and heading into the military, so this is likely his last birthday at home for a while. Things have been really hard financially for months. I’m just now starting to get a little breathing room, but I’m so far behind that there’s no way I can pull anything together.

My car isn’t working, so I can’t go anywhere, and it’s 20 degrees outside, which means walking to the store isn’t an option. We don’t live in a walkable area anyway. We’ve got cereal and a few basics at home, but I can’t make him a proper meal, and I have nothing for him to open. He deserves so much more than this, and I feel like I’m failing him. I’ve always found creative ways to celebrate even when money’s tight, like grabbing balloons or small surprises from Dollar Tree, but that’s just not possible right now.

If anyone has any ideas—anything at all—I’d be so grateful. Whether it’s something I can do with what we have at home, a creative way to make the day memorable, or just encouragement, I’d really appreciate it. It’s breaking my heart to see him step into adulthood and into such a brave path without being able to make this moment feel as special as it should. If anyone has any suggestions or ways to help, thank you from the bottom of my heart.

Hello people i am a 26 yo male living in france, i started to work as a cook since september in a Social restaurant. I must say this is a great working place for me, they treat me well, i learn a lot of things, and i love the food. However, those past weeks, i noticed my heart beat is very fast before or during sleep, and i am very anxious during my sleep. i'm no quit sure about where it comes from. When i ask myself what makes me anxious, i think it comes from the future. Just the though of having to move out from my parent house makes me very scared. The thought of having no one to trust or to count on is also very stressful. I am constantly in doubt and have sometimes no confidence even if i accomplish things i tend to forget them and only remember the negative aspect in my life. Thank you for reading this post, writting out feels like i take out things that weigh in my heart.

​

“If you know your stress levels (when and how stressed you are), do you think breathing techniques help, and have you tried them?”

Hi everyone,

Over the past few months, I’ve been on a journey to better manage my anxiety, and one thing that’s really made a difference is focusing on movement. For the longest time, I struggled with staying consistent—most fitness apps felt either too intense or too rigid, which only added to my stress.

That’s when I started paying closer attention to stress patterns in my own life. I’ve even been exploring tools like Lume, which helps me spot when my stress levels are rising before I feel it, and gives me personalized tips to adjust.

It’s been eye-opening to realize how interconnected everything is. If you’re curious about these ideas, I shared more in a recent article I wrote: Anxiety: It's Not You, It's Your Metabolism.

Would love to hear how others are navigating anxiety and finding balance. What’s been working for you?

How do you cope with financial stress?

How do you cope with financial stress?

Is there anything like this in the books or online? It used to help me reduce stress when I practiced "I don't care approach".

I walked out of my room this morning and looked around the house the bathroom the kitchen the living room is absolutely trashed. Dishes in the sink for a week without being rinsed after they got used. bathroom has clothes ear picks and hair everywhere. And I'm not sure what to do he's always been super messy even when he lived with his parents I told him before we moved in together I'm fine with his room being a wreck but not the house. My old house had 9 people in it and no one cleaned and mice were running rapid I never want to live in a dirty environment again, when I walked out of my room this morning my head got really hot my heart started racing and I just feel fuxking awful! I clean the bathroom every couple days and it just gets wrecked over and over again he just doesn't clean up after himself whatsoever I just hope he gets his shit together and I'll let it be known. If it continues I'll just have to accept the financial burden of living alone I'm just so stressed out and I feel like I shouldn't be but I can't help it 😭

It’s like it’s something that I feel is off . Feels like inflammation behind my eyes or around my eyes. Not sure . Then heart or chest area feeling slightly strained . Not sure if it’s the heart directly although it feels like it . Then just feeling like unknown inflammation in my body

For years, I was constantly anxious, stressed, and exhausted. I didn’t know my breathing patterns were a big part of why.

I was a chest breather. My breaths were shallow, quick, and all in my upper chest. This way of breathing wasn’t random—it was a learned habit from years of stress.

Here’s what happens when you breathe like this:

• Your body uses more energy to breathe.
• You signal to your brain that you’re in danger.
• Your heart rate stays elevated, and stress chemicals flood your system.

The worst part? I didn’t even know this was happening. I thought feeling anxious and exhausted was my new “normal.” No doctor or therapist had ever addressed my breathing habits.

One day, I stumbled on something that shifted everything: Dysfunctional breathing fuels your stress. Functional breathing calms it.

Here’s how I re-trained my breath:

1. Nasal Breathing

Your nose is designed for breathing—it filters air, slows it down, and improves oxygen uptake. I only started breathing in and out through my nose as much as possible.

2. Slow Down

Stress makes you breathe fast and shallow. I practiced slowing my breath to 5-6 breaths per minute. Long, slow exhales calm your nervous system faster than any pill.

3. Breathe Deep into the Ribs

Instead of chest breathing, I learned to expand my lower ribs with every inhale. This is diaphragmatic breathing: gentle, slow, and efficient.

I did this for just 10 minutes a day. Slowly, I felt a shift:

• My anxiety wasn’t as constant.

• My heart rate lowered.

• My mind felt clearer.

Proper breathing doesn’t just calm your mind—it teaches your body to feel safe again.

If you’re stuck in stress, anxiety, or burnout like I was, start here:

• Breathe through your nose.

• Keep your breath gentle, slow, and expansive.

• Practice 10 minutes a day.

The results will start to transform your relationship with stress and anxiety.

Hi everyone,
I wanted to share something that’s been life-changing for me and might resonate with others here. For a long time, I thought of anxiety as purely a mental health issue. Therapy and mindfulness helped, but I always felt like there was something missing. Then I stumbled upon the book Brain Energy by Dr. Christopher Palmer, and it completely shifted my perspective.

The idea that anxiety might be connected to metabolic health — influenced by what we eat and how we move — was a game-changer. Since then, I’ve made some changes in my diet (goodbye, sugar and processed foods) and committed to regular exercise. It’s not a quick fix, but I’ve noticed real improvements.

I wrote an article about this journey, where I dive into how lifestyle changes like eating unprocessed foods, exercising, and using tools like the Lume app helped me. If this resonates, I’d love for you to check it out and share your thoughts.

Here’s the link: https://medium.com/@mazenkurdi/anxiety-its-not-you-it-s-your-metabolism-b04f896eea64

Also, what’s worked for you in managing anxiety? I’d love to hear your experiences!