ESR8 - Strength Scaling in Fibre Networks

Name: Mossab Alzweighi

ESR no.: 8

Description of the IRP:

Paper-based materials are recognized to have a disordered structure and to show stochastic variations in their mechanical properties. These variations lead to occasional failures that cannot be predicted by deterministic materials. Inability to account for the stochastic nature of failures often leads to over-dimensioning paper products, resulting in a greater consumption of natural materials and a higher production cost.

The importance of strength distribution has been identified in connection with failures of products made of fiber-based materials. Both the network strength and strength distribution are size-dependent in fiber-based materials. With increased linear size, the average strength decreases. At the same time, the strength distribution follows the extreme Weibull distribution with a long tail toward zero.

In this project, we will derive the factors that contribute to the strength distributions of the fiber-based materials at relevant sizes from which the strength scaling applies and develop an up-scaling technique to connect the strength statistics from the micro- and mesoscale to the product scale strength statistics. Micromechanical computational tools will be used to connect the variability of the constitutive response of paper products with properties of raw materials and important process parameters.

The ultimate goal is to predict strength uniformity parameters from a microscale analysis and discover the factors controlling them. Which is essential for predicting the performance of the fiber-based materials in end-use applications and saving material by selecting appropriate safety factors.


  • Micromechanics, strength distribution, fiber-based material, stochastic, Weibull, constitutive modeling, up-scaling technique.

About the ESR:

I come originally from Syria and currently, I am a Ph.D. student at the KTH Royal Institute of Technology where I will carry out my research aiming at developing my knowledge in micromechanical structures. Prior to that, I worked at Lappeenranta University of Technology in machine design laboratory and participated in the Virtual-Sensor project, where I used a computational procedure to estimate stresses and forces that applied to mechanical systems when the real sensors cannot be used. Also, I have accomplished my master's degree in applied mechanics from St.Petersburg Polytechnic University with master's thesis entitled "Defining contact forces in high-speed rotor systems based on finite element modeling". Furthermore, I worked as a teaching assistant at Tishreen University after completing my bachelor's degree in mechanical engineering from the same university. During my leisure time, chess is my favorite hobby also reading and traveling are of interest.


Contact information:

  • Mossab Alzweighi
  • KTH Royal Institute of Technology
  • Department of solid mechanics, Teknikringen 8D, SE-100 44, Stockholm, Sweden