JLR Suspension Knuckle
Jaguar Land Rover’s Ravi Londhe — Lead AVA-CAE Templates Engineer — set our team a live industry brief: design a rear one-piece suspension knuckle meeting three performance targets: mass reduction, structural stiffness, and natural frequency. Working within a five-person team, I took ownership of structural FEA and additive manufacturing feasibility research.
The knuckle was redesigned in A356 aluminium — a 66% mass reduction over the original cast steel baseline — with sand casting and post-process CNC machining selected as the optimal production route. ANSYS Workbench confirmed the design met all three brief objectives: peak stress at 13% of material yield, deformation under 0.02 mm, and safety factors consistently above 2.5 under both static and harmonic loading.
Technical Breakdown
Model & Assembly
The knuckle was designed from scratch in Fusion 360, with supporting suspension components sourced from the SolidWorks library and assembled into a representative suspension system for integration validation — confirming correct fitment and clearance at all mounting interfaces before committing to manufacture.
Industry-standard design practices applied throughout: correct draft angles for casting, tolerancing on all mating faces, and geometry optimised for manufacture and assembly. A fully detailed engineering drawing was produced — ready to hand directly to a manufacturer.
FEA — Static & Harmonic
A 4,200 N vertical load was applied representing real-world suspension loading. Results confirmed all three brief objectives: peak stress at just 13% of A356 yield strength (16.3 MPa of 125 MPa), maximum deformation under 0.02 mm, and safety factors of 5–15 across the component.
Harmonic response analysis identified critical frequency peaks in the 400–2,000 Hz engine vibration range and near 5,000 Hz from tyre imbalance — the regions where lightweight aluminium knuckles are most vulnerable to fatigue and joint loosening. The analysis confirmed the geometry avoids the worst resonance modes, satisfying the frequency objective.
Additive Manufacture Feasibility
A PLA prototype was 3D printed for form verification and physical display. Beyond this, I investigated whether high-performance additive manufacture could serve as a viable production route — evaluating FDM in PPS-CF filament (168 MPa tensile, 227 °C heat resistance) and DMLS in titanium alloy as the highest-performance alternative.
The conclusion: FDM is unsuitable for a safety-critical suspension component. Layer-by-layer deposition creates inherent anisotropy that cannot guarantee consistent structural integrity under dynamic loading. DMLS is structurally viable but cost-prohibitive at automotive production volumes. Sand casting with CNC finishing is the correct production route.
Die Casting & CNC Machining
Team’s selected manufacturing route — I contributed through shrinkage calculations, draft angle analysis, and mould geometry review. Primary showcase of mould design and CNC machining knowledge. Top : 8-part sand casting mould with M16 clamping and spill catches. Bottom: CNC machining simulation — slot cutting for bearing retaining ring.
Sand casting with post-process CNC machining was selected as the primary production route, with a die-cast variant developed as a high-volume alternative. Mounting holes were omitted from the cast geometry and finished to tolerance by CNC in a subsequent operation. The sand casting mould was designed as an 8-part assembly, incorporating M16 clamping features, pouring holes, and recessed spill catches.
Draft angles of 2–3° for sand casting and 0.5–1° for die casting were applied throughout, with A356’s 6.5% linear shrinkage accounted for in the cavity geometry. Post-casting CNC milling then finished all critical faces and bores — delivering the best balance of cost, precision, and scalability for a road-vehicle production component.