Journal Browser

Journal Browser

Special Issue "Variable Stiffness Composite Materials and Structures"

A special issue of Materials (ISSN 1996-1944). This special issue belongs to the section "Materials Simulation and Design".

Deadline for manuscript submissions: closed (10 May 2022) | Viewed by 970

Special Issue Editors

Dr. Humberto Almeida Jr.
E-Mail Website
Guest Editor
Advanced Composites Research Group, School of Mechanical and Aerospace Engineering, Queen’s University Belfast, Belfast, UK
Interests: variable stiffness composites; uncertainty quantification; structural optimization; post-buckling; damage modeling; advanced manufacturing
Dr. Saullo G. P. Castro
E-Mail Website
Guest Editor
Group of Aerospace Structures and Computational Mechanics, Department of Aerospace Structures and Materials, Faculty of Aerospace Engineering, Delft University of Technology, Delft, The Netherlands
Interests: design; optimization and analysis of lightweight structures; design under non-linear constraints; advanced methods for post-buckling analysis; fluid-structure interaction

Special Issue Information

Dear Colleagues,

This Special Issue (SI) of Materials of MDPI, titled “Variable Stiffness Composite Materials and Structures”, addresses advances in variable stiffness structures, where variable stiffness is achieved by means of curvilinear fibers, variable fiber volume content, variable thickness, or any combination thereof. Studies investigating variable stiffness metallic structures for lightweight applications are also welcome.

With the advent of novel manufacturing methods, different nomenclatures have been proposed for composites containing curvilinear fibers, the most well known being variable stiffness, variable-axial, variable angle tow, tow-steered composites, and curvilinear fiber-reinforced composites. Such classes of composites have been successfully applied to improve several properties when compared to straight-fiber laminated composites, and this SI welcomes new studies investigating tailored static and mechanical properties, such as natural frequencies, aeroelastic behavior, critical buckling load, post-buckling behavior, minimum compliance, and strength. For studies dealing with lightweight applications, but not exclusively, preference will be given to those aiming at optimized weight, performance, fuel consumption per passenger per kilogram, or any other metrics aiming towards more sustainable designs. Studies aiming at applications not directly related to lightweight application are also welcome, and should be aimed at tailored static or dynamic mechanical behavior enabled by the variable stiffness properties, or should show the unique advantages of using variable stiffness materials.

Investigations into the fatigue and damage tolerance (FDT) of variable stiffness composite structures are extremely welcome, given the relative reduced number of studies in this direction. How does the FDT behavior of variable stiffness composites compare to traditional ones? How is the FDT behavior affected by design parameters? How does a crack initiate and propagate in variable stiffness composites? These are examples of research questions this SI is aiming at.

Other topics that are welcome in this SI are novel and robust computational models that accurately describe the behavior of variable stiffness composite materials, including the presence of gaps and overlaps, when applicable; and new or improved manufacturing techniques.

If you have any questions or suggestions, please do not hesitate to contact the two guest editors of this SI, who will be pleased to be in touch at their earliest convenience.

Best Regards,

Dr. Humberto Almeida Jr.
Dr. Saullo G. P. Castro
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Materials is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2300 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.


  • variable stiffness
  • variable angle tow
  • variable-axial
  • tow-steered
  • curvilinear fiber composites
  • mechanical performance
  • optimization
  • tailoring aeroelastic behavior
  • tailoring mechanical behavior
  • stiffness tailoring
  • manufacturing constraints
  • uncertainty quantification
  • damage tolerance

Published Papers (1 paper)

Order results
Result details
Select all
Export citation of selected articles as:


Lightweight Design of Variable-Stiffness Cylinders with Reduced Imperfection Sensitivity Enabled by Continuous Tow Shearing and Machine Learning
Materials 2022, 15(12), 4117; - 09 Jun 2022
Viewed by 499
The present study investigates how to apply continuous tow shearing (CTS) in a manufacturable design parameterization to obtain reduced imperfection sensitivity in lightweight, cylindrical shell designs. The asymptotic nonlinear method developed by Koiter is applied to predict the post-buckled stiffness, whose index is [...] Read more.
The present study investigates how to apply continuous tow shearing (CTS) in a manufacturable design parameterization to obtain reduced imperfection sensitivity in lightweight, cylindrical shell designs. The asymptotic nonlinear method developed by Koiter is applied to predict the post-buckled stiffness, whose index is constrained to be positive in the optimal design, together with a minimum design load. The performance of three machine learning methods, namely, Support Vector Machine, Kriging, and Random Forest, are compared as drivers to the optimization towards lightweight designs. The new methodology consists of contributions in the areas of problem modeling, the selection of machine learning strategies, and an optimization formulation that results in optimal designs around the compromise frontier between mass and stiffness. The proposed ML-based framework proved to be able to solve the inverse problem for which a target design load is given as input, returning as output lightweight designs with reduced imperfection sensitivity. The results obtained are compatible with the existing literature where hoop-oriented reinforcements were added to obtain reduced imperfection sensitivity in composite cylinders. Full article
(This article belongs to the Special Issue Variable Stiffness Composite Materials and Structures)
Show Figures

Figure 1

Back to TopTop