Nijandhan, KMuralikannan, RThimiri Govindaraj, Deepak BPradeesh, EL2025-09-082025-09-082025-031023-666X1563-5341https://doi.org/10.1080/1023666X.2025.2477562http://hdl.handle.net/10204/14391This investigation focused on identifying the effect of fiber parameters (fiber length, fiber weight) on the mechanical properties of pretreated caster fiber-reinforced polyester composites. The composite plates were fabricated using the hand layup technique by varying the fiber length and fiber content in polyester matrix composites. The tensile, flexural, and impact tests were conducted as per ASTM standards. Fracture mechanism was analyzed using scanning electron microscopy (SEM) images. It is found that the highest tensile (20.8 MPa), flexural (46.4 MPa), and impact (38.2 kJ/m2) strengths of composites with 30 mm fiber length and 40% fiber wt. content. The regression equation was formulated and optimum fiber parameters for better mechanical properties were identified using response surface methodology and pattern search optimization algorithm. This study confirms that caster fiber-reinforced polyester composites were used to lightweight engineering applications.AbstractenCaster fiber compositesMechanical propertiesScanning electron microscopySEMResponse surface methodologyRSMPattern search optimizationArticlen/a