# Conceptual Design of Composite Bridge Sandwich Structure
## 1 Introduction
[PERSON] [22] worked on the structural development of FRP composite bridge deck intended for manufacturing. Stiffness and strength evaluation was done for a novel FRP sandwich panel for bridge redecking. Wood is an alternative material, distinguished by significant environmental benefits, relatively low cost, and fairly good mechanical properties [23]. It has been shown that wood and FRP materials can work well together when bonded [24]. Quite recently, light wood is used as the material of core in the FRP sandwich bridge deck due to its low cost and excellent flexural properties. This offers a more cost-effective alternative for core materials in sandwich systems for civil applications. [PERSON] [25] evaluated the actions of wood bridge beams reinforced with carbon/epoxy composites. The findings of their analysis revealed that the use of carbon/epoxy composite laminates to reinforce wood bridge beams has resulted in a substantial improvement in both bending and shear strength with a modest improvement in beam stiffness. Good strength-to-weight ratios and stiffness-to-weight ratios render balsa wood a popular option for sandwich cores. In bridge construction, the first efforts are ongoing to substitute honeycomb and foam components with better-performing balsa wood as the main material for composites bridge decks, e.g., for the 56-m Bascule Footbridge in Norway [26]. Bamboo has also recently been investigated as a construction material in a mixture of FRP composites due to its satisfactory character. Paulownia wood is also emerging in the field with excellent mechanical properties. Composite materials' mechanical properties typically depend on their configuration and are affected by several factors, such as, composition, reinforcement, anisotropic, inhomogeneity shape, adhesion, fiber orientation, manufacturing process, etc. For a composite material application, mechanical testing is the most critical aspect. When the micro-mechanics and failure mechanism of composites are studied, it is challenging compared to with isotropic materials. Mechanisms of failure and related theory are measured for the bridges, depending on the amount, the quality of reinforcement, and structure. Here, the finite element analysis (FEA) of a bridge deck was performed using ANSYS WORKBENCH. The analysis was carried out on a slab-type bridge with a fixed length and width. If the length and width are changed, there will be a significant effect on all the parameters. [PERSON] [27] worked on different spans of the bridge. Starting from 16 m length, the maximum length he achieved was 19 m. Beyond these lengths, the deflection was too high and cannot fulfill the criteria span/500. So he used a girder under the slab to increase the span up to 30 m.  
According to the bridge sketch, a geometrical prototype of the bridge was made. Suitable modules with computationally feasible mesh sizes were selected. The properties of materials were applied by specifications. Boundary conditions and specific loads were applied after the preprocessing stage. The findings were related to the specifications on design. To create a composite bridge for different loads under ULS and SLS conditions was the ultimate goal of this project. Geometrically, the bridge was similar to the slab, and it's both ends were fixed on the banks of passage. The top and bottom laminates were constructed from face sheets of glass fibers and carbon fibers, and three different kinds of woods were used in the core. Different combinations of angles between plies and fabrics were used and compared to the specifications of the design.