Compliant closed-cell joints do not buckle under compression and exhibit a higher axial-to-rotational stiffness ratio than conventional compliant joints by using a fluid encapsulated in a flexible cell as the main load-bearing element. However, the axial and shear stiffness are still insufficient to replace spherical or universal joints in high load-bearing applications. This thesis aims to address this by using a fiber-reinforced cell wall. To make optimal use of the fiber strength, adapted geodesic-isotensoid designs are proposed.
To evaluate the performance of different geodesic-isotensoid designs, an axial mathematical model was developed and validated with a finite element model. Furthermore, both models were used to evaluate the axial, rotational, and shear stiffness, as well as the load-bearing capacity of the joint across a range of designs. The results can be used to guide the design of future fiber-reinforced compliant closed-cell joints. Additionally, it was found that adding extra fibers increases axial stiffness without affecting rotational stiffness, enabling high axial-to-rotational stiffness ratios.

This study introduces a novel constraint in linkage mechanism design: the constant-area constraint. Traditional linkage mechanisms rely on constraints of rigidity and joint motion, the constant-area constraint enforces an additional limitation:  the area enclosed by the linkages remains constant throughout its motion. Originating from incompressible fluid mechanics, this concept is adapted for linkage mechanisms. We present computational tools developed for analysing and optimising constant-area linkage mechanisms. These tools are applied to explore their kinematic behaviour and possibilities. This novel concept led to a modification of the Gruebler degrees-of-freedom formula. The constant area concept is applied to five- and six-bar mechanisms and an exploratory analysis of multiple interconnected constant area cells is also conducted.

Hydrostatic bearings are typically designed to operate on flat, parallel surfaces, but a flexible hydrostatic bearing that can adapt to uneven smooth surfaces would have broader applications. This thesis focuses on the challenges of implementing the whiffletree concept to support a large, deformable hydrostatic bearing on wavy surfaces, which cannot be achieved with the current design due to four significant complications. To overcome these issues, the thesis proposes modifications to the whiffletree concept and introduces the multi-joint suspension system, which has greater potential to support a large, flexible hydrostatic bearing.

Conventional hydrostatic bearings are not suited to use on surfaces with changing curvature which limits their applicability. To improve on this, deformable hydrostatic bearings are currently being researched. The goal of this work is to develop hydrostatic bearings with a single fluid supply that work for sinusoidal counter surfaces.

The bearing pad of a deformable hydrostatic bearing must be able to conform to the shape of the sinusoidal counter surface at any position while being able to carry high loads. Previous research has also pointed out that a deformable hydrostatic bearing should have a triangular contact pressure profile for compression against a flat surface. This way a bearing without preference towards either the concave or convex part on a sinusoidal counter surface should be obtained.

The design problem is translated into a problem formulation for the synthesis of compliant mechanisms with topology optimization. In this formulation strain energies of the design domain under different load cases are utilized to achieve selective stiffness. In an extension of the formulation, the reaction forces under uniform vertical compression of the structure are required to attain a triangular shaped profile. This requirement is relaxed in the second extension where the reaction forces are only required to monotonically decrease from the middle to the sides.

Optimizations without requirement on the reaction profile yield interesting structures with clear-cut boundaries. When implementing the requirement on the reaction profile, there appears to be a trade-off between achieving the prescribed shape and the presence of grey area and artifacts in the designs. The optimizer tends to employ distributed compliance to meet the requirement, which can compromise the load-bearing capabilities of the structures.

Evaluation of selected results with a contact model predicts that numerous obtained designs could function as a hydrostatic bearing on a sinusoidal counter surface with an amplitude of 11.3 mm. Additional effort with a more realistic evaluation model is required to draw a definite conclusion on the performance.